meta-agl-bsp: update NXP weston bbappend name

meta-agl-bsp: update NXP weston bbappend name

Update weston_*.imx.bbappend name for the new 12.0.3 version in
meta-freescale that came in with the scarthgap 5.0.1 bump.

Bug-AGL: SPEC-5212

Change-Id: I69ce5489a8494cb0076cc57949e3c301f7e8f98d
Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl/+/30137
Reviewed-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>
ci-image-build: Jenkins Job builder account
Tested-by: Jenkins Job builder account
ci-image-boot-test: Jenkins Job builder account