Revert "bcma: Kconfig: Let it depend on PCI"

This reverts commit b09f5ec1.

Now that we have fully working BCMA_DRIVER_PCI symbol (in can be safely
disabled), there is no risk bcma will try to use PCI code without PCI
available.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>