olpc-xo1 uses pci_*() interfaces so it should depend on PCI.

Otherwise we get build failure like:

 arch/x86/kernel/olpc-xo1.c:65: error: implicit declaration of function 'pci_enable_device_io'
 arch/x86/kernel/olpc-xo1.c:71: error: implicit declaration of function 'pci_request_region'
 arch/x86/kernel/olpc-xo1.c:80: error: implicit declaration of function 'pci_release_region'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Daniel Drake <dsd@laptop.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
LKML-Reference: <20101014101313.adf7eb2a.randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>