V4L/DVB (10150): ttusb-dec: make it depend on PCI

Since ttusb_dec.c relies on pci_alloc_consistent and
pci_free_consistent, make it depend on PCI in Kconfig.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>