checkpatch: ignore ETHTOOL_LINK_MODE_ enum values

checkpatch: ignore ETHTOOL_LINK_MODE_ enum values

Since commit 4104a20646 ("checkpatch: ignore generated CamelCase defines
and enum values") enum values like ETHTOOL_LINK_MODE_Asym_Pause_BIT are
ignored.  But there are other enums like
ETHTOOL_LINK_MODE_1000baseT_Full_BIT, which are not ignored because of the
not matching '1000baseT' substring.

Add regex to match all ETHTOOL_LINK_MODE enums.

Link: https://lkml.kernel.org/r/20230104201524.28078-1-gerhard@engleder-embedded.com
Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Gerhard Engleder <gerhard@engleder-embedded.com>
Cc: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>