sh: Use local TLB flush in set_pte_phys().

set_pte_phys() presently uses the global flush_tlb_one(), which locks on
SMP trying to do the IPI. As we have not even initialized the other CPUs
at this point, switch to the local_ variant so the flush happens on the
boot CPU.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>