w1: add 1-wire master driver for i.MX27 / i.MX31

This patch adds support for the 1-wire master interface for i.MX27 and
i.MX31.

Signed-off-by: Luotao Fu <l.fu@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/w1/masters/Kconfig b/drivers/w1/masters/Kconfig
index 9061682..96d2f8e 100644
--- a/drivers/w1/masters/Kconfig
+++ b/drivers/w1/masters/Kconfig
@@ -34,6 +34,12 @@
 	  This driver can also be built as a module.  If so, the module
 	  will be called ds2482.
 
+config W1_MASTER_MXC
+	tristate "Freescale MXC 1-wire busmaster"
+	depends on W1 && ARCH_MXC
+	help
+	  Say Y here to enable MXC 1-wire host
+
 config W1_MASTER_DS1WM
 	tristate "Maxim DS1WM 1-wire busmaster"
 	depends on W1 && ARM && HAVE_CLK