MLK-18577-7 imx8qm: mek: support uboot in vm

MLK-18577-7 imx8qm: mek: support uboot in vm

We are targeting let uboot loading images from emmc to boot android.
Currently only emmc1 is enabled, so other devices are disabled.

Also change memory layout according to VM layout. The memory layout
needs to be samesize as what you configured in as "memory = "3584"".

Add a new dts dedicated for this kind uboot, add a new defconfig
to select CONFIG_XEN/CONFIG_XEN_DEBUG_SERIAL, deselect CONFIG_DM_SERIAL,
select CONFIG_ENABLE_ARM_SOC_BOOT0_HOOK, and disable some devices
compared with imx8qm_mek_androidauto_defconfig.

Reviewed-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
(cherry picked from commit a4e932cae433b9d2e1cff6a94b12e4abcac45543)
(cherry picked from commit a26de6e05563d3e3e6734e0d99e464437aa89db5)
(cherry picked from commit 74ac579ee195c4a2f6651ccc0f86efb0eebd889e)
(cherry picked from commit 7258e558b51a7f56d2b895c9c554423e12037ed3)