com20020: Fix allyesconfig build failure.
com20020: Fix allyesconfig build failure.

Reported by Stephen Rothwell.

Due to missing 'extern' in the com20020_netdev_ops declaration,
each file that includes linux/com20020.h gets another copy
defined in it's resulting object file.

Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas