memory: add a driver for atmel ram controllers

Atmel SoCs have one or multiple RAM controllers that need one or multiple clocks
to run.
This driver handle those clocks.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index c59e9c9..257061c 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -7,6 +7,16 @@
 
 if MEMORY
 
+config ATMEL_SDRAMC
+	bool "Atmel (Multi-port DDR-)SDRAM Controller"
+	default y
+	depends on ARCH_AT91 && OF
+	help
+	  This driver is for Atmel SDRAM Controller or Atmel Multi-port
+	  DDR-SDRAM Controller available on Atmel AT91SAM9 and SAMA5 SoCs.
+	  Starting with the at91sam9g45, this controller supports SDR, DDR and
+	  LP-DDR memories.
+
 config TI_AEMIF
 	tristate "Texas Instruments AEMIF driver"
 	depends on (ARCH_DAVINCI || ARCH_KEYSTONE) && OF