MIPS R2 documents state that an execution hazard barrier is needed
after a TLBR before reading EntryLo.

Original patch by Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/5526/