spi: bcm53xx: driver for SPI controller on Broadcom bcma SoC

Broadcom 53xx ARM SoCs use bcma bus that contains various cores (AKA
devices). If board has a serial flash, it's connected over SPI and the
bcma bus includes a SPI controller. Example log from such a board:
bus0: Found chip with id 53010, rev 0x00 and package 0x02
(...)
bus0: Core 18 found: SPI flash controller (manuf 0x4BF, id 0x50A, rev 0x01, class 0x0)

This patch adds a bcma driver for SPI core, it registers SPI master
controller and "bcm53xxspiflash" SPI device.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 62e2242..b14b829 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -112,6 +112,12 @@
 	  If you say yes to this option, support will be included for the
 	  PSC SPI controller found on Au1550, Au1200 and Au1300 series.
 
+config SPI_BCM53XX
+	tristate "Broadcom BCM53xx SPI controller"
+	depends on ARCH_BCM_5301X
+	help
+          Enable support for the SPI controller on Broadcom BCM53xx ARM SoCs.
+
 config SPI_BCM63XX
 	tristate "Broadcom BCM63xx SPI controller"
 	depends on BCM63XX