MIPS: Kconfig: Avoid build errors by hiding USE_OF from the user.
MIPS: Kconfig: Avoid build errors by hiding USE_OF from the user.

b01da9f1 ("MIPS: Prune some target specific code out of prom.c") removed
the generic implementation of device_tree_init, breaking the kernel
build when manually selecting USE_OF.

Hide the config symbol so it can't be selected acidentially anymore.

Signed-off-by: Jonas Gorski <9712c064bde5a52658fc87d6454b4956f9bf286b@gmail.com>
Cc: 562397917b9a8bf316569a848858b12fb417723f@linux-mips.org
Cc: David Daney <eec15f2dea0e7d114bf41a5bde8a2858b8f3e893@cavium.com>
Patchwork: https://patchwork.linux-mips.org/patch/4346/
Signed-off-by: Ralf Baechle <92f48d309cda194c8eda36aa8f9ae28c488fa208@linux-mips.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas