mediatek: remove KERNEL_PATCHVER overwrite for mt7629

Since whole target has been bumped to kernel 4.19 in 01c8f2e9
("mediatek: bump to v4.19") we do not need the overwrite in mt7629
subtarget anymore.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

target/linux/mediatek/mt7629/target.mk

@@ -9,7 +9,6 @@ CPU_TYPE:=cortex-a7
 FEATURES:=squashfs nand ramdisk
 
 KERNELNAME:=Image dtbs
-KERNEL_PATCHVER:=4.19
 
 define Target/Description
 	Build firmware images for MediaTek mt7629 ARM based boards.