esp-qcom-image: add back support for KERNEL_CMDLINE_EXTRA

KERNEL_CMDLINE_EXTRA addition to the kernel command line was removed as
part of the switch to the oe-core uki.bbclass, add it back.

Signed-off-by: Ricardo Salveti <ricardo.salveti@oss.qualcomm.com>

Author: ricardosalveti

recipes-kernel/images/esp-qcom-image.bb

@@ -13,6 +13,7 @@ inherit image uki uki-esp-image
 UKI_FILENAME = "${EFI_LINUX_IMG}"
 
 UKI_CMDLINE = "root=${QCOM_BOOTIMG_ROOTFS} rw rootwait console=${KERNEL_CONSOLE}"
+UKI_CMDLINE += "${@'' + d.getVar('KERNEL_CMDLINE_EXTRA') if d.getVar('KERNEL_CMDLINE_EXTRA') else ''}"
 
 # Remove 'upstream' dtb, rely on EFI provided one
 KERNEL_DEVICETREE = ""
@@ -34,3 +35,5 @@ remove_unused_files() {
     find ${IMAGE_ROOTFS} -mindepth 1 ! -path "${IMAGE_ROOTFS}/EFI*" -exec rm -rf {} +
 }
 IMAGE_PREPROCESS_COMMAND:append = " remove_unused_files"
+
+do_uki[vardeps] += "KERNEL_CMDLINE_EXTRA"