[media] b2c2: break it into common/pci/usb directories

b2c2 is, in fact, 2 drivers: one for PCI and one for USB, plus
a common bus-independent code. Break it accordingly.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/usb/Kconfig b/drivers/media/usb/Kconfig
index 70b1708..53664b3 100644
--- a/drivers/media/usb/Kconfig
+++ b/drivers/media/usb/Kconfig
@@ -14,5 +14,6 @@
 source "drivers/media/usb/ttusb-budget/Kconfig"
 source "drivers/media/usb/ttusb-dec/Kconfig"
 source "drivers/media/usb/siano/Kconfig"
+source "drivers/media/usb/b2c2/Kconfig"
 
 endif