[POWERPC] fix PMU initialization on pseries lpar

We should not be calling power4_enable_pmcs() in
pseries_lpar_enable_pmcs(); just doing the hypercall is sufficient.
Prior to 2.6.15 we did not call power4_enable_pmcs() for an lpar.

power4_enable_pmcs() tries to read the hid0 register which is no
longer legal for an lpar in newer Power processors.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

arch/powerpc/platforms/pseries/setup.c

@@ -213,8 +213,6 @@ static void pseries_lpar_enable_pmcs(void)
 {
 	unsigned long set, reset;
 
-	power4_enable_pmcs();
-
 	set = 1UL << 63;
 	reset = 0;
 	plpar_hcall_norets(H_PERFMON, set, reset);