drivers: Add the common directory and files for SPI

Add the necessary Kconfig, Makefile etc...

Change-Id: I3682ab353ef71f3827520ab3fc4b16a122180d99
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>

drivers/Kconfig

@@ -49,4 +49,6 @@ source "drivers/random/Kconfig"
 
 source "drivers/pci/Kconfig"
 
+source "drivers/spi/Kconfig"
+
 endmenu

drivers/Makefile

@@ -10,3 +10,4 @@ obj-y += interrupt_controller/
 obj-$(CONFIG_PCI) += pci/
 obj-$(CONFIG_BLUETOOTH) += bluetooth/
 obj-$(CONFIG_UART_SIMPLE) += simple/
+obj-$(CONFIG_SPI) += spi/

drivers/spi/Kconfig

@@ -0,0 +1,49 @@
+# Kconfig - SPI driver configuration options
+
+#
+# Copyright (c) 2015 Intel Corporation
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# 1) Redistributions of source code must retain the above copyright notice,
+# this list of conditions and the following disclaimer.
+#
+# 2) Redistributions in binary form must reproduce the above copyright notice,
+# this list of conditions and the following disclaimer in the documentation
+# and/or other materials provided with the distribution.
+#
+# 3) Neither the name of Intel Corporation nor the names of its contributors
+# may be used to endorse or promote products derived from this software without
+# specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+
+#
+# SPI Drivers
+#
+menuconfig SPI
+	bool
+	prompt "SPI hardware bus support"
+	default n
+	help
+	  Enable support for the SPI hardware bus.
+
+config  SPI_DEBUG
+	bool
+	prompt "SPI drivers debug output"
+	depends on SPI
+	default n
+	help
+	  Enable debug output for SPI drivers