mfd: pm8921: Loosen Kconfig dependency

Allow this driver to be compiled on all ARM builds as it doesn't
rely on anything within arm/mach-msm.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/Kconfig

@@ -478,7 +478,7 @@ config MFD_PM8XXX
 
 config MFD_PM8921_CORE
 	tristate "Qualcomm PM8921 PMIC chip"
-	depends on (ARCH_MSM || HEXAGON)
+	depends on (ARM || HEXAGON)
 	select IRQ_DOMAIN
 	select MFD_CORE
 	select MFD_PM8XXX