parisc: Remove pte_inserted define

The attached change removes the pte_inserted from pgtable.h.  As a
result, we always flush the TLB entry when the associated page table
entry is changed.

This change doesn't impact performance signifcantly and it may catch
some cases where the TLB needs flushing but wasn't.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>