Convert CONFIG_SPL_LIBGENERIC_SUPPORT to Kconfig

Move this option to Kconfig and tidy up existing uses.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig
index ce48d25..d0cc86e 100644
--- a/arch/arm/mach-tegra/Kconfig
+++ b/arch/arm/mach-tegra/Kconfig
@@ -6,6 +6,9 @@
 config SPL_LIBCOMMON_SUPPORT
 	default y
 
+config SPL_LIBGENERIC_SUPPORT
+	default y
+
 config TEGRA_IVC
 	bool "Tegra IVC protocol"
 	help