LS1043ARBD: Fix SD Boot issue with PPA

CONFIG_SPL_FSL_LS_PPA is needed only in case of falcon boot
Support for this is not present in PPA currently, so
removing the default option from defconfig

Signed-off-by: Vinitha V Pillai <vinitha.pillai@nxp.com>
Signed-off-by: Ruchika Gupta <ruchika.gupta@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>