armv8: ls1028ardb: add xspi parameter to qixis command

Add xspi boot source to qixis command to let the soc boot from
flex-nor flash chip.

Signed-off-by: Yuantian Tang <andy.tang@nxp.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
2 files changed