[MTD] CK804XROM must depend on PCI

CONFIG_MTD_CK804XROM=y, CONFIG_PCI=n results in the following compile
error:

  CC      drivers/mtd/maps/ck804xrom.o
ck804xrom.c: In function 'ck804xrom_init_one':
ck804xrom.c:114: error: implicit declaration of function 'pci_dev_get'
ck804xrom.c:114: warning: assignment makes pointer from integer without a cast
make[4]: *** [drivers/mtd/maps/ck804xrom.o] Error 1

Considering what hardware this driver is driving, a dependency on PCI
also seems logical.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Ryan Jackson <rjackson@lnxi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>