add ONIE_PLATFORM_EXTRA_CMDLINE_LINUX to kernel bootparam

Author: prgeor

platform/marvell-armhf/platform.conf

@@ -176,8 +176,7 @@ prepare_boot_menu() {
     fi
     BORDER='echo "---------------------------------------------------";echo;'
     fw_setenv ${FW_ARG} print_menu "$BORDER $BOOT1 $BOOT2 $BOOT3 $BORDER" > /dev/null
-
-    fw_setenv ${FW_ARG} linuxargs "net.ifnames=0 loopfstype=squashfs loop=$image_dir/$FILESYSTEM_SQUASHFS systemd.unified_cgroup_hierarchy=0 varlog_size=$VAR_LOG_SIZE loglevel=4 ${extra_cmdline_linux}" > /dev/null
+    fw_setenv ${FW_ARG} linuxargs "net.ifnames=0 loopfstype=squashfs loop=$image_dir/$FILESYSTEM_SQUASHFS systemd.unified_cgroup_hierarchy=0 varlog_size=$VAR_LOG_SIZE loglevel=4 ${extra_cmdline_linux} ${ONIE_PLATFORM_EXTRA_CMDLINE_LINUX}" > /dev/null
     fw_setenv ${FW_ARG} linuxargs_old "net.ifnames=0 loopfstype=squashfs loop=$image_dir_old/$FILESYSTEM_SQUASHFS systemd.unified_cgroup_hierarchy=0 varlog_size=$VAR_LOG_SIZE loglevel=4" > /dev/null
 
     # Set boot configs