fcntl: Use consistent values for F_[GS]ETOWN_EX

These values were only introduced during this release cycle, so it is
still early enough to get them right.

alpha uses the same values that are in asm-generic/fcntl.h, so just
remove them.

parisc uses the values interchanged for no apparent reason, so remove
them to give us consistency across all architectures.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>