drivers: misc: add Gateworks System Controller driver

Add a driver for the Gateworks System Controller used on Gateworks boards
which provides a boot watchdog, power control, temperature monitor,
and voltage ADCs.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index cf060da..bde298c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -882,6 +882,12 @@
 F:	drivers/watchdog/sp805_wdt.c
 F:	drivers/watchdog/sbsa_gwdt.c
 
+GATEWORKS_SC
+M:	Tim Harvey <tharvey@gateworks.com>
+S:	Maintained
+F:	drivers/misc/gsc.c
+F:	include/gsc.h
+
 I2C
 M:	Heiko Schocher <hs@denx.de>
 S:	Maintained