[PATCH] Move the identical files from include/asm-ppc{,64}

Move the identical files from include/asm-ppc{,64}/ to
include/asm-powerpc/.  Remove hdreg.h completely as it is unused in
the tree.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>