mfd: syscon: atmel-smc: Add new helpers to ease SMC regs manipulation

Add helper functions for atmel Static Memory Controller. The functions
are required to configure SMC. This file is inherited from the work
done by Boris Brezillon for Linux

Signed-off-by: Balamanikandan Gunasundar <balamanikandan.gunasundar@microchip.com>
diff --git a/drivers/Makefile b/drivers/Makefile
index 6f1de58..83b14ef 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -103,6 +103,7 @@
 obj-$(CONFIG_U_QE) += qe/
 obj-y += mailbox/
 obj-y += memory/
+obj-y += mfd/
 obj-y += mtd/
 obj-y += pwm/
 obj-y += reset/