GPIO_VX855: eliminate kconfig dependency warning

Fix kconfig dependency warning to satisfy dependencies:

warning: (GPIO_VX855 && GPIOLIB) selects MFD_VX855 which has unmet direct dependencies (MFD_SUPPORT && PCI)

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Daniel Drake <dsd@laptop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>