brcmsmac: select CONFIG_BCMA when possible

The brcmsmac relies BCMA functionality to access the device. This
patch selects CONFIG_BCMA when CONFIG_BCMA_POSSIBLE is set. This
way the user does not need to be select BCMA to make the brcmsmac
driver show up in his menuconfig.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/brcm80211/Kconfig

@@ -4,7 +4,8 @@ config BRCMUTIL
 config BRCMSMAC
 	tristate "Broadcom IEEE802.11n PCIe SoftMAC WLAN driver"
 	depends on MAC80211
-	depends on BCMA
+	depends on BCMA_POSSIBLE
+	select BCMA
 	select BRCMUTIL
 	select FW_LOADER
 	select CRC_CCITT