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>

arch/arm/mach-tegra/Kconfig

@@ -15,6 +15,9 @@ config SPL_SERIAL_SUPPORT
 config TEGRA_CLKRST
 	bool
 
+config TEGRA_GP_PADCTRL
+	bool
+
 config TEGRA_IVC
 	bool "Tegra IVC protocol"
 	help
@@ -61,6 +64,7 @@ config TEGRA_ARMV7_COMMON
 	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 @@ config TEGRA210
 	select TEGRA_ARMV8_COMMON
 	select TEGRA_CLKRST
 	select TEGRA_GPIO
+	select TEGRA_GP_PADCTRL
 	select TEGRA_NO_BPMP
 
 config TEGRA186

arch/arm/mach-tegra/Makefile

@@ -13,7 +13,7 @@ else
 obj-$(CONFIG_CMD_ENTERRCM) += cmd_enterrcm.o
 endif
 
-obj-y += ap.o
+obj-$(CONFIG_TEGRA_GP_PADCTRL) += ap.o
 obj-y += board.o board2.o
 obj-y += cache.o
 obj-$(CONFIG_TEGRA_CLKRST) += clock.o

arch/arm/mach-tegra/cache.c

@@ -8,7 +8,9 @@
 #include <common.h>
 #include <asm/io.h>
 #include <asm/arch-tegra/ap.h>
+#if IS_ENABLED(CONFIG_TEGRA_GP_PADCTRL)
 #include <asm/arch/gp_padctrl.h>
+#endif
 
 #ifndef CONFIG_ARM64
 void config_cache(void)