boards: versalnet_apu: Add QEMU support via west and Twister

Add support for running the APU ELF on QEMU using the
`west build -t run_qemu` target. QEMU integration is now wired through
west and Twister for the `versalnet_apu` board.

Signed-off-by: Appana Durga Kedareswara rao <appana.durga.kedareswara.rao@amd.com>