ARM: tegra: Guard memory controller code with a Kconfig symbol

Memory controller 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 265051b..5763c4a 100644
--- a/arch/arm/mach-tegra/Kconfig
+++ b/arch/arm/mach-tegra/Kconfig
@@ -26,6 +26,9 @@
 	  U-Boot, it is typically used for communication between the main CPU
 	  and various auxiliary processors.
 
+config TEGRA_MC
+	bool
+
 config TEGRA_COMMON
 	bool "Tegra common options"
 	select BINMAN
@@ -65,6 +68,7 @@
 	select TEGRA_COMMON
 	select TEGRA_GPIO
 	select TEGRA_GP_PADCTRL
+	select TEGRA_MC
 	select TEGRA_NO_BPMP
 
 config TEGRA_ARMV8_COMMON
@@ -111,6 +115,7 @@
 	select TEGRA_CLKRST
 	select TEGRA_GPIO
 	select TEGRA_GP_PADCTRL
+	select TEGRA_MC
 	select TEGRA_NO_BPMP
 
 config TEGRA186