brcm63xx: drop linux,part-probe usage where possible

It was present as 4.4 compatibility, but since we now use 4.9 or later
with the new upstream solution, we don't need it anymore.

This also fixes a serious regression introduced by ac9bcefa3b, which
changed the precedence of linux,part-probe and the new-type partitions
node compatible string, causing caldata partitions to be overwritten.

Fixes: ac9bcefa3b ("kernel: use V10 of mtd patchset adding support for "compatible" string")
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
(cherry picked from commit 7880a6f7fe)

target/linux/brcm63xx/dts/usr9108.dts

@@ -30,8 +30,6 @@
 &pflash {
 	status = "ok";
 
-	linux,part-probe = "bcm63xxpart";
-
 	partitions {
 		compatible = "fixed-partitions";
 		#address-cells = <1>;