spi: controller driver for Designware SPI core

Driver for the Designware SPI core, it supports multipul interfaces like
PCI/APB etc.  User can use "dw_apb_ssi_db.pdf" from Synopsys as HW
datasheet.

[randy.dunlap@oracle.com: fix build]
[akpm@linux-foundation.org: build fix]
Signed-off-by: Feng Tang <feng.tang@intel.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 07e5453..d7c1741 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -292,6 +292,16 @@
 # Add new SPI master controllers in alphabetical order above this line
 #
 
+config SPI_DESIGNWARE
+	bool "DesignWare SPI controller core support"
+	depends on SPI_MASTER
+	help
+	  general driver for SPI controller core from DesignWare
+
+config SPI_DW_PCI
+	tristate "PCI interface driver for DW SPI core"
+	depends on SPI_DESIGNWARE && PCI
+
 #
 # There are lots of SPI device types, with sensors and memory
 # being probably the most widely used ones.