boards: nxp: imx95_evk: add M7 DDR board variant

Add DDR variant of the i.MX95 EVK board (M7 core). Using this
variant, one can run Zephyr from DDR instead of ITCM/DTCM
as it's the case for the M7 "base" board.

Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>