ramips: mt76x8: disable unused Ralink systick driver

ramips: mt76x8: disable unused Ralink systick driver

The mt76x8 series SoCs use the MIPS generic systick timer. Sync the
upstream Ralink systick driver changes and disable it for mt76x8
target to reduce the kernel size.

Signed-off-by: Shiji Yang <yangshiji66@qq.com>
Link: https://github.com/openwrt/openwrt/pull/16844
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
(cherry picked from commit 0c57510cedeff9caf795930ff86a436aa54bcc6d)
Link: https://github.com/openwrt/openwrt/pull/17097
Signed-off-by: Petr Štetiar <ynezz@true.cz>