spi: Add driver for Marvell Armada 3700 SoC

The SPI IP core in the Marvell Armada 3700 is similar to the one in the
other Armada SoCs. But the differences are big enough that it makes
sense to introduce a new driver instead of cluttering the old
kirkwood driver with #ifdef's.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Nadav Haklai <nadavh@marvell.com>
Cc: Kostya Porotchkin <kostap@marvell.com>
Cc: Wilson Ding <dingwei@marvell.com>
Cc: Victor Gu <xigu@marvell.com>
Cc: Hua Jing <jinghua@marvell.com>
Cc: Terry Zhou <bjzhou@marvell.com>
Cc: Hanna Hawa <hannah@marvell.com>
Cc: Haim Boot <hayim@marvell.com>
Reviewed-by: Jagan Teki <jteki@openedev.com>
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 5da66a6..8724f87 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -68,6 +68,13 @@
 	  access the SPI NOR flash on platforms embedding this Intel
 	  ICH IP core.
 
+config MVEBU_A3700_SPI
+	bool "Marvell Armada 3700 SPI driver"
+	help
+	  Enable the Marvell Armada 3700 SPI driver. This driver can be
+	  used to access the SPI NOR flash on platforms embedding this
+	  Marvell IP core.
+
 config PIC32_SPI
 	bool "Microchip PIC32 SPI driver"
 	depends on MACH_PIC32