ARM: socfpga: Add syscon to be part of socfpga

SOCFPGA has a system manager register block can be accessed by using
the syscon driver.

Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
Cc: Pavel Machek <pavel@denx.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <olof@lixom.net>
Cc: <linux@arm.linux.org.uk>
Signed-off-by: Olof Johansson <olof@lixom.net>

arch/arm/mach-socfpga/Kconfig

@@ -13,5 +13,6 @@ config ARCH_SOCFPGA
 	select GPIO_PL061 if GPIOLIB
 	select HAVE_ARM_SCU
 	select HAVE_SMP
+	select MFD_SYSCON
 	select SPARSE_IRQ
 	select USE_OF