Convert CONFIG_IOMUX_SHARE_CONF_REG et al to Kconfig

This converts the following to Kconfig:
   CONFIG_IOMUX_LPSR
   CONFIG_IOMUX_SHARE_CONF_REG

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/mach-imx/mx6/Kconfig b/arch/arm/mach-imx/mx6/Kconfig
index 752c57f..e6b0ee7 100644
--- a/arch/arm/mach-imx/mx6/Kconfig
+++ b/arch/arm/mach-imx/mx6/Kconfig
@@ -168,6 +168,7 @@
 	select BOARD_LATE_INIT
 	select DM
 	select DM_THERMAL
+	select IOMUX_LPSR
 
 config TARGET_DART_6UL
 	bool "Variscite imx6ULL dart(DART-SOM-6ULL)"
@@ -396,6 +397,7 @@
 	select BOARD_LATE_INIT
 	select DM
 	select DM_THERMAL
+	select IOMUX_LPSR
 	imply CMD_DM
 
 config TARGET_MX6SXSABRESD
@@ -464,6 +466,7 @@
 	select BOARD_LATE_INIT
 	select DM
 	select DM_THERMAL
+	select IOMUX_LPSR
 	imply CMD_DM
 
 config TARGET_MX6ULZ_SMM_M2