Kconfig: Migrate CONFIG_BAUDRATE

Move this in to Kconfig with a default of 115200.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
[trini: Run moveconfig.py, reword commit slightly]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/evb-rk3399_defconfig b/configs/evb-rk3399_defconfig
index 7ef7cb0..bedc1fd 100644
--- a/configs/evb-rk3399_defconfig
+++ b/configs/evb-rk3399_defconfig
@@ -43,6 +43,7 @@
 CONFIG_PWM_ROCKCHIP=y
 CONFIG_RAM=y
 CONFIG_SPL_RAM=y
+CONFIG_BAUDRATE=1500000
 CONFIG_DEBUG_UART=y
 CONFIG_DEBUG_UART_BASE=0xFF1A0000
 CONFIG_DEBUG_UART_CLOCK=24000000