net: fill in MODULE_DESCRIPTION()s for 8390

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to all the good old 8390 modules and drivers.

Signed-off-by: Breno Leitao <leitao@debian.org>
CC: geert@linux-m68k.org
Link: https://lore.kernel.org/r/20240123190332.677489-2-leitao@debian.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>