MIPS: Netlogic: Handle XLP hardware errata

Core configuration register IFU_BRUB_RESERVE has to be setup to handle
a silicon errata which can result in a CPU hang.

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8902/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>