bcma: allow disabling (not building) PCI driver

It isn't required for bcma bus on SoCs, so provide some empty functions
and allow disabling it.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
diff --git a/drivers/bcma/Kconfig b/drivers/bcma/Kconfig
index 9be17d3..1500b71 100644
--- a/drivers/bcma/Kconfig
+++ b/drivers/bcma/Kconfig
@@ -45,9 +45,9 @@
 
 	  If unsure, say N
 
-# TODO: make it depend on PCI when ready
 config BCMA_DRIVER_PCI
-	bool
+	bool "BCMA Broadcom PCI core driver"
+	depends on BCMA && PCI
 	default y
 	help
 	  BCMA bus may have many versions of PCIe core. This driver