spmi: Debug-fs support for SPMI

Add user space interface to the SPMI kernel framework that enables
master-read and master-write transactions.

Each SPMI controller is represented as a file under the root directory
of SPMI debug-fs.  For each controller, 'address', 'count', and 'data'
files are added.  The user may configure the transaction via the
respective files and invoke a master read transaction by reading from
the 'data' file, and a master write transaction by writing a string of
decimal or hexadecimal byte size values to the 'data' file.

Change-Id: I3e760be7796bfb9aa15c8ab758ff616a72240176
Signed-off-by: Gilad Avidov <gavidov@codeaurora.org>
Signed-off-by: Kenneth Heitke <kheitke@codeaurora.org>
diff --git a/drivers/spmi/Makefile b/drivers/spmi/Makefile
index becd823..2161fac 100644
--- a/drivers/spmi/Makefile
+++ b/drivers/spmi/Makefile
@@ -4,3 +4,7 @@
 obj-$(CONFIG_SPMI)			+= spmi.o spmi-resources.o
 obj-$(CONFIG_SPMI_MSM_PMIC_ARB)		+= spmi-pmic-arb.o
 obj-$(CONFIG_MSM_QPNP_INT)		+= qpnp-int.o
+
+ifdef CONFIG_DEBUG_FS
+obj-$(CONFIG_SPMI)			+= spmi-dbgfs.o
+endif