The ppc32 and ppc64 versions of cacheflush.h were almost identical.
The two versions of cache.h are fairly similar, except for a bunch of
register definitions in the ppc32 version which probably belong better
elsewhere.  This patch, therefore, merges both headers.  Notable
points:
	- there are several functions in cacheflush.h which exist only
on ppc32 or only on ppc64.  These are handled by #ifdef for now, but
these should probably be consolidated, along with the actual code
behind them later.
	- Confusingly, both ppc32 and ppc64 have a
flush_dcache_range(), but they're subtly different: it uses dcbf on
ppc32 and dcbst on ppc64, ppc64 has a flush_inval_dcache_range() which
uses dcbf.  These too should be merged and consolidated later.
	- Also flush_dcache_range() was defined in cacheflush.h on
ppc64, and in cache.h on ppc32.  In the merged version it's in
cacheflush.h
	- On ppc32 flush_icache_range() is a normal function from
misc.S.  On ppc64, it was wrapper, testing a feature bit before
calling __flush_icache_range() which does the actual flush.  This
patch takes the ppc64 approach, which amounts to no change on ppc32,
since CPU_FTR_COHERENT_ICACHE will never be set there, but does mean
renaming flush_icache_range() to __flush_icache_range() in
arch/ppc/kernel/misc.S and arch/powerpc/kernel/misc_32.S
	- The PReP register info from asm-ppc/cache.h has moved to
arch/ppc/platforms/prep_setup.c
	- The 8xx register info from asm-ppc/cache.h has moved to a
new asm-powerpc/reg_8xx.h, included from reg.h
	- flush_dcache_all() was defined on ppc32 (only), but was
never called (although it was exported).  Thus this patch removes it
from cacheflush.h and from ARCH=powerpc (misc_32.S) entirely.  It's
left in ARCH=ppc for now, with the prototype moved to ppc_ksyms.c.

Built for Walnut (ARCH=ppc), 32-bit multiplatform (pmac, CHRP and PReP
ARCH=ppc, pmac and CHRP ARCH=powerpc).  Built and booted on POWER5
LPAR (ARCH=powerpc and ARCH=ppc64).

Built for 32-bit powermac (ARCH=ppc and ARCH=powerpc).  Built and
booted on POWER5 LPAR (ARCH=powerpc and ARCH=ppc64).  Built and booted
on G5 (ARCH=powerpc)
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>