[ethtool]: disable unit test when building ethtool on armhf/arm64 (#7226)

Compiling ethtool from source is causing ethtool unit tests to fail on ARM Platforms.

These tests are failing: (By default netlink-interface is enabled while compiling ethtool)
Link: ([Test File Link](https://salsa.debian.org/kernel-team/ethtool/-/blob/debian/1%255.9-1/test-cmdline.c#L28))
```
FAIL: test-cmdline
==================

E: ethtool 16_char_devname! returns 1
E: ethtool 
127_char_devname0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcde returns 1
E: ethtool --change devname xcvr external returns 0
E: ethtool --change devname speed 100 duplex half port tp autoneg on advertise 0x1 phyad 1 xcvr external wol p sopass 01:23:45:67:89:ab msglvl 1 returns 0

FAIL test-cmdline (exit status: 1)
```
Tested this on Local ARM Emulated Container:

```
(Docker Container Emulating ARM)
vkarri@3a03c70eed35:/tmp/ethtool$ ./ethtool 16_char_devname!
netlink interface initialization failed, device name longer than 15 not supported
vkarri@3a03c70eed35:/tmp/ethtool$ echo $?
1 (Expected 0)
vkarri@3a03c70eed35:~/ethtool$ ./ethtool 16_char_devnameee
netlink interface initialization failed, device name longer than 15 not supported

Checked for dependencies: (all are present)
vkarri@3a03c70eed35:~/ethtool$ apt-cache policy libmnl0
libmnl0:
  Installed: 1.0.4-2
  Candidate: 1.0.4-2
  Version table:
 *** 1.0.4-2 500
        500 http://deb.debian.org/debian buster/main armhf Packages
        500 http://packages.trafficmanager.net/debian/debian buster/main armhf Packages
        100 /var/lib/dpkg/status

vkarri@3a03c70eed35:~/ethtool$ apt-cache policy libc6  
libc6:
  Installed: 2.28-10
  Candidate: 2.28-10
  Version table:
 *** 2.28-10 500
        500 http://deb.debian.org/debian buster/main armhf Packages
        500 http://packages.trafficmanager.net/debian/debian buster/main armhf Packages
        100 /var/lib/dpkg/status
```

#### How I did it
Disabled netlink-interface for ethtool. 

Even though Netlink is not available, it doesn't seem to impact what ethtool was supposed to do. In fact the older version which was in use before this PR [#5725](#5725) did not have netlink support and everything seemed to work well

Article on Netlink-Support for ethtool: https://lwn.net/Articles/783633/

Signed-off-by: Vivek Reddy Karri <[email protected]>

Author: vivekrnv

rules/ethtool.mk

@@ -3,11 +3,11 @@
 ETHTOOL_VERSION_BASE = 5.9
 export ETHTOOL_VERSION_BASE
 
-ETHTOOL = ethtool_$(ETHTOOL_VERSION_BASE)-1_amd64.deb
+ETHTOOL = ethtool_$(ETHTOOL_VERSION_BASE)-1_$(CONFIGURED_ARCH).deb
 $(ETHTOOL)_SRC_PATH = $(SRC_PATH)/ethtool
 SONIC_MAKE_DEBS += $(ETHTOOL)
 
-ETHTOOL_DBG = ethtool-dbgsym_$(ETHTOOL_VERSION_BASE)-1_amd64.deb
+ETHTOOL_DBG = ethtool-dbgsym_$(ETHTOOL_VERSION_BASE)-1_$(CONFIGURED_ARCH).deb
 $(eval $(call add_extra_package,$(ETHTOOL),$(ETHTOOL_DBG)))
 
 export ETHTOOL ETHTOOL_DBG

src/ethtool/Makefile

@@ -12,7 +12,12 @@ $(addprefix $(DEST)/, $(MAIN_TARGET)): $(DEST)/% :
 	pushd ethtool
 	git checkout tags/debian/1%$(ETHTOOL_VERSION_BASE)-1
 	# Build package
+ifneq (,(filter $(CONFIGURED_ARCH),arm64 armhf))
+	DEB_BUILD_OPTIONS=nocheck dpkg-buildpackage -rfakeroot -b -us -uc -j$(SONIC_CONFIG_MAKE_JOBS) --admindir $(SONIC_DPKG_ADMINDIR)
+else
 	dpkg-buildpackage -rfakeroot -b -us -uc -j$(SONIC_CONFIG_MAKE_JOBS) --admindir $(SONIC_DPKG_ADMINDIR)
+endif
+	
 	popd
 	mv $(DERIVED_TARGET) $* $(DEST)/