sunxi: Add AXP_PMIC_BUS kconfig entry

Add simple and meaningful kconfig option for pmic_bus.c
instead of using MACH type on Makefile.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
index 2fd372a..1a179e1 100644
--- a/arch/arm/mach-sunxi/Kconfig
+++ b/arch/arm/mach-sunxi/Kconfig
@@ -23,6 +23,12 @@
 	  Support for the PRCM (Power/Reset/Clock Management) unit available
 	  in A31 SoC.
 
+config AXP_PMIC_BUS
+	bool "Sunxi AXP PMIC bus access helpers"
+	help
+	  Select this PMIC bus access helpers for Sunxi platform PRCM or other
+	  AXP family PMIC devices.
+
 config SUN8I_RSB
 	bool "Allwinner sunXi Reduced Serial Bus Driver"
 	help