hwmon: pm8921-adc: Add sysfs interface

-Add sysfs interface to read PM8921 HK/XOADC
and thermistor temperature measurements mapped
through MPP's.
-Move PM8921 ADC from directory /drivers/mfd to
/drivers/hwmon for userspace clients to read ADC
through hwmon.

CRs-Fixed: 302365
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>

Conflicts:

	drivers/mfd/Kconfig
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index eacfcb5..c25ffcb 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -120,6 +120,7 @@
 obj-$(CONFIG_SENSORS_WM8350)	+= wm8350-hwmon.o
 obj-$(CONFIG_SENSORS_WPCE775X)	+= wpce775x.o
 obj-$(CONFIG_SENSORS_MSM_ADC)	+= msm_adc.o m_adcproc.o
+obj-$(CONFIG_SENSORS_PM8921_ADC)	+= pm8921-adc.o msmproc_adc.o
 
 # PMBus drivers
 obj-$(CONFIG_PMBUS)		+= pmbus_core.o