brcm63xx: Livebox 1: fix part probe name

Fix the DTS file for the Livebox 1 routers:
- part probe wrong, it should be RedBoot (uppercase matters)

Signed-off-by: Daniel Gonzalez Cabanelas <dgcbueu@gmail.com>
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>

target/linux/brcm63xx/dts/livebox-blue-5g.dts

@@ -68,5 +68,5 @@
 	reg = <0x1e400000 0x800000>;
 	status = "ok";
 
-	linux,part-probe = "redboot";
+	linux,part-probe = "RedBoot";
 };