ARM: tegra: Guard clock code with a Kconfig symbol

Clock 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 86b1cd1..ee078fe 100644
--- a/arch/arm/mach-tegra/Kconfig
+++ b/arch/arm/mach-tegra/Kconfig
@@ -12,6 +12,9 @@
 config SPL_SERIAL_SUPPORT
 	default y
 
+config TEGRA_CLKRST
+	bool
+
 config TEGRA_IVC
 	bool "Tegra IVC protocol"
 	help
@@ -55,6 +58,7 @@
 	select SPL
 	select SPL_BOARD_INIT if SPL
 	select SUPPORT_SPL
+	select TEGRA_CLKRST
 	select TEGRA_COMMON
 	select TEGRA_GPIO
 	select TEGRA_NO_BPMP
@@ -100,6 +104,7 @@
 config TEGRA210
 	bool "Tegra210 family"
 	select TEGRA_ARMV8_COMMON
+	select TEGRA_CLKRST
 	select TEGRA_GPIO
 	select TEGRA_NO_BPMP