ARM: dts: imx: Migrate iMX6QDL picoITX DTs from Linux

Migrate DH picoITX device trees from Linux commit 42226c989789
(tag v5.18-rc7). No changes have been made, the DTs are exact copies.
Furthermore add the DTB to dh_imx6_defconfig.

Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Philip Oberfichtner <pro@denx.de>