Convert CONFIG_TEGRA_ENABLE_UARTA et al to Kconfig

This converts the following to Kconfig:
   CONFIG_TEGRA_ENABLE_UARTA
   CONFIG_TEGRA_ENABLE_UARTB
   CONFIG_TEGRA_ENABLE_UARTC
   CONFIG_TEGRA_ENABLE_UARTD
   CONFIG_TEGRA_SPI
   CONFIG_TEGRA_UARTA_GPU
   CONFIG_TEGRA_UARTA_SDIO1
   CONFIG_TEGRA_VDD_CORE_TPS62361B_SET3
   CONFIG_TEGRA_VDD_CORE_TPS62366A_SET1

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/plutux_defconfig b/configs/plutux_defconfig
index 170ac86..789b5d9 100644
--- a/configs/plutux_defconfig
+++ b/configs/plutux_defconfig
@@ -10,6 +10,7 @@
 CONFIG_SYS_PROMPT="Tegra20 (Plutux) # "
 CONFIG_TEGRA20=y
 CONFIG_TARGET_PLUTUX=y
+CONFIG_TEGRA_ENABLE_UARTD=y
 CONFIG_SYS_LOAD_ADDR=0x1000000
 CONFIG_FIT=y
 CONFIG_OF_SYSTEM_SETUP=y