net: arcnet: com20020-isa: add missing MODULE_DESCRIPTION() macro

With ARCH=m68k, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/arcnet/com20020-isa.o

Add the missing invocation of the MODULE_DESCRIPTION() macro.

Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240618-md-m68k-drivers-net-arcnet-v1-1-90e42bc58102@quicinc.com


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