ssb: add Kconfig entry for compiling SoC related code

This allows saving a little of space when not using ssb on Broadcom SoC.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
diff --git a/drivers/ssb/Kconfig b/drivers/ssb/Kconfig
index f0d22cd..149214b 100644
--- a/drivers/ssb/Kconfig
+++ b/drivers/ssb/Kconfig
@@ -80,6 +80,15 @@
 
 	  If unsure, say N
 
+config SSB_HOST_SOC
+	bool "Support for SSB bus on SoC"
+	depends on SSB
+	help
+	  Host interface for a SSB directly mapped into memory. This is
+	  for some Broadcom SoCs from the BCM47xx and BCM53xx lines.
+
+	  If unsure, say N
+
 config SSB_SILENT
 	bool "No SSB kernel messages"
 	depends on SSB && EXPERT