[PATCH] ppc32: perfctl-ppc: fix duplicate mmcr0 define

Fix a compilation warning due to a duplicate definition of MMCR0_PMXE.

The definition comes in perfctr-ppc.patch, but was recently introduced too
in Linus tree.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/asm-ppc/reg.h

@@ -333,7 +333,6 @@
 #define MMCR0_PMC2_CYCLES	0x1
 #define MMCR0_PMC2_ITLB		0x7
 #define MMCR0_PMC2_LOADMISSTIME	0x5
-#define MMCR0_PMXE		(1 << 26)
 
 /* Short-hand versions for a number of the above SPRNs */
 #define CTR	SPRN_CTR	/* Counter Register */