[PATCH] ppc64: Move ppc64_enable_pmcs() logic into a ppc_md function

This patch moves power4_enable_pmcs() to arch/ppc64/kernel/pmc.c.

I've tested it on P5 LPAR and P4. It does what it used to.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>