configs: imx6q_logic: Move CONFIG_MXC_UART to Kconfig

Since CONFIG_MXC_UART is already in Kconfig, move this from
the header to imx6q_logic_defconfig

Signed-off-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Stefano Babic <sbabic@denx.de>
diff --git a/configs/imx6q_logic_defconfig b/configs/imx6q_logic_defconfig
index bd0da25..a13034d 100644
--- a/configs/imx6q_logic_defconfig
+++ b/configs/imx6q_logic_defconfig
@@ -39,3 +39,4 @@
 CONFIG_PINCTRL_IMX6=y
 CONFIG_DM_PMIC_PFUZE100=y
 CONFIG_DM_REGULATOR_PFUZE100=y
+CONFIG_MXC_UART=y