hplance: fix ram size in comment

drivers/net/ethernet/amd/hplance.h:
 #define HPLANCE_MEMOFF 0x8000   /* struct lance_init_block */
 #define HPLANCE_NVRAMOFF 0xC008 /* etheraddress as one *nibble* per byte */

The offset of RAM start is 0x8000, the offset of RAM end is 0xC008,
so the RAM size is 16392 bytes.

Signed-off-by: Amos Kong <akong@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>