[PARISC] Update bitops from parisc tree

Optimize ext2_find_next_zero_bit. Gives about 25% perf improvement with a
rsync test with ext3.

Signed-off-by: Randolph Chung <tausq@parisc-linux.org>

fix ext3 performance - ext2_find_next_zero() was culprit.
Kudos to jejb for pointing out the the possibility that ext2_test_bit
and ext2_find_next_zero() may in fact not be enumerating bits in
the bitmap because of endianess. Took sparc64 implementation and
adapted it to our tree. I suspect the real problem is ffz() wants
an unsigned long and was getting garbage in the top half of the
unsigned int. Not confirmed but that's what I suspect.

Signed-off-by: Grant Grundler <grundler@parisc-linux.org>

Fix find_next_bit for 32-bit
Make masking consistent for bitops

From: Joel Soete <soete.joel@tiscali.be>
Signed-off-by: Randolph Chung <tausq@parisc-linux.org>

Add back incorrectly removed ext2_find_first_zero_bit definition

Signed-off-by: James Bottomley <jejb@parisc-linux.org>

Fixup bitops.h to use volatile for *_bit...