ARM: tegra: Guard GP pad control code with a Kconfig symbol

The GP pad control code is not relevant on all Tegra SoC generations, so
guard it with a Kconfig symbol that can be selected by the generations
that need it.

This is in preparation for unifying Tegra186 code with the code used on
older generations.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig
index ee078fe..265051b 100644
--- a/arch/arm/mach-tegra/Kconfig
+++ b/arch/arm/mach-tegra/Kconfig
@@ -15,6 +15,9 @@
 config TEGRA_CLKRST
 	bool
 
+config TEGRA_GP_PADCTRL
+	bool
+
 config TEGRA_IVC
 	bool "Tegra IVC protocol"
 	help
@@ -61,6 +64,7 @@
 	select TEGRA_CLKRST
 	select TEGRA_COMMON
 	select TEGRA_GPIO
+	select TEGRA_GP_PADCTRL
 	select TEGRA_NO_BPMP
 
 config TEGRA_ARMV8_COMMON
@@ -106,6 +110,7 @@
 	select TEGRA_ARMV8_COMMON
 	select TEGRA_CLKRST
 	select TEGRA_GPIO
+	select TEGRA_GP_PADCTRL
 	select TEGRA_NO_BPMP
 
 config TEGRA186