bcma: add trivial GBIT MAC COMMON driver

GMAC COMMON core is present on BCM4706 and is used for example to access
board PHYs (PHYs can not be accessed directly using GBIT MAC core).

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/bcma/Kconfig

@@ -46,6 +46,15 @@ config BCMA_DRIVER_MIPS
 
 	  If unsure, say N
 
+config BCMA_DRIVER_GMAC_CMN
+	bool "BCMA Broadcom GBIT MAC COMMON core driver"
+	depends on BCMA
+	help
+	  Driver for the Broadcom GBIT MAC COMMON core attached to Broadcom
+	  specific Advanced Microcontroller Bus.
+
+	  If unsure, say N
+
 config BCMA_DEBUG
 	bool "BCMA debugging"
 	depends on BCMA