sh: Fix up more 64-bit pgprot truncation on SH-X2 TLB.

Both the store queue API and the PMB remapping take unsigned long for
their pgprot flags, which cuts off the extended protection bits. In the
case of the PMB this isn't really a problem since the cache attribute
bits that we care about are all in the lower 32-bits, but we do it just
to be safe. The store queue remapping on the other hand depends on the
extended prot bits for enabling userspace access to the mappings.

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