ARM: dts: imx6q-logicpd: Add missing imx6q-logicpd-u-boot for SPL

The SPL device tree is missing the entires for gpio1, uart1, usdhc1 and
usdhc2.  This creates the missing imx6q-logicpd-u-boot.dtsi file
which will enable these functions so SPL can properly setup UART, detect
microSD card, and startup.

Fixes: 8f4691e3 ("ARM: imx6q_logic: With SPL_OF_CONTROL enabled,
remove MMC init")

Signed-off-by: Adam Ford <aford173@gmail.com>