r8152: fix the maximum number of PLA bp for RTL8153C

The maximum PLA bp number of RTL8153C is 16, not 8. That is, the
bp 0 ~ 15 are at 0xfc28 ~ 0xfc46, and the bp_en is at 0xfc48.

Fixes: 195aae32 ("r8152: support new chips")
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>