patches/openwrt: mpc85xx: stay on kernel 5.10 for now

In some cases on Turris 1.x devices the eth2 (WAN) is not
working. We don't know what is happening exactly right now. We are not
able to reproduce it even though we have same setup, it is working for
us. Other things are working as they should.

patches/openwrt/wip/0000-mpc85xx-and-mvebu-switch-to-kernel-5.15.patch

@@ -17,7 +17,7 @@ index b1771dfd8e..35d08b12d1 100644
  SUBTARGETS:=p1010 p1020 p2020
  
 -KERNEL_PATCHVER:=5.4
-+KERNEL_PATCHVER:=5.15
++KERNEL_PATCHVER:=5.10
 +KERNEL_TESTING_PATCHVER:=5.15
  
  KERNELNAME:=zImage