include: env: phytec: Add optargs to K3 files

Add the optargs variable so that we can set optional arguments while
booting.

Signed-off-by: Nathan Morrisson <nmorrisson@phytec.com>
Signed-off-by: Daniel Schultz <d.schultz@phytec.de>
diff --git a/include/env/phytec/k3_mmc.env b/include/env/phytec/k3_mmc.env
index ad8d3a8..3f67e31 100644
--- a/include/env/phytec/k3_mmc.env
+++ b/include/env/phytec/k3_mmc.env
@@ -11,6 +11,7 @@
 
 mmcargs=setenv bootargs console=${console} earlycon=${earlycon}
 	root=/dev/mmcblk${mmcdev}p${mmcroot} ${raucargs} rootwait rw
+	${optargs}
 mmcloadimage=load mmc ${mmcdev}:${mmcpart} ${kernel_addr_r} Image
 mmcloadfdt=load mmc ${mmcdev}:${mmcpart} ${fdt_addr_r} ${fdtfile}
 mmcboot=if test ${doraucboot} = 1; then run raucinit; fi;