memory: gpmc: Move omap gpmc code to live under drivers

Just move to drivers as further clean-up can now happen there
finally.

Let's also add Roger and me to the MAINTAINERS so we get
notified for any patches related to GPMC.

Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index 6d91c27..6759de7 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -41,6 +41,14 @@
 	  parameters and other settings during frequency, voltage and
 	  temperature changes
 
+config OMAP_GPMC
+	bool
+	help
+	  This driver is for the General Purpose Memory Controller (GPMC)
+	  present on Texas Instruments SoCs (e.g. OMAP2+). GPMC allows
+	  interfacing to a variety of asynchronous as well as synchronous
+	  memory drives like NOR, NAND, OneNAND, SRAM.
+
 config MVEBU_DEVBUS
 	bool "Marvell EBU Device Bus Controller"
 	default y