kernel: ltq-adsl-mei: Fix compilation with Linux 5.15

struct of_device_id is not implicitly included anymore. Include
<linux/mod_devicetable.h> to fix compilation on Linux 5.15.

Signed-off-by: Martin Blumenstingl <[email protected]>

package/kernel/lantiq/ltq-adsl-mei/src/drv_mei_cpe.c

@@ -28,6 +28,7 @@
 
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/mod_devicetable.h>
 #include <linux/version.h>
 #include <generated/utsrelease.h>
 #include <linux/types.h>