MIPS: mm: tlb-r4k: Uniquify TLB entries on init

MIPS: mm: tlb-r4k: Uniquify TLB entries on init

Hardware or bootloader will initialize TLB entries to any value, which
may collide with kernel's UNIQUE_ENTRYHI value. On MIPS microAptiv/M5150
family of cores this will trigger machine check exception and cause boot
failure. On M5150 simulation this could happen 7 times out of 1000 boots.

Replace local_flush_tlb_all() with r4k_tlb_uniquify() which probes each
TLB ENTRIHI unique value for collisions before it's written, and in case
of collision try a different ASID.

Cc: stable@kernel.org
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>