powerpc/e500mc: Remove dead L2 flushing code in idle_e500.S

This code can never be executed as it is only built when
CONFIG_PPC_E500MC is unset, but the only CPUs that have CPU_FTR_L2CSR
require CONFIG_PPC_E500MC and do not have the MSR/HID0-based nap
mechanism that this file uses.
Signed-off-by: Scott Wood <scottwood@freescale.com>

arch/powerpc/kernel/idle_e500.S

@@ -58,15 +58,6 @@ BEGIN_FTR_SECTION
 	mtlr	r0
 	lis	r3,HID0_NAP@h
 END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
-BEGIN_FTR_SECTION
-	msync
-	li	r7,L2CSR0_L2FL@l
-	mtspr	SPRN_L2CSR0,r7
-2:
-	mfspr	r7,SPRN_L2CSR0
-	andi.	r4,r7,L2CSR0_L2FL@l
-	bne	2b
-END_FTR_SECTION_IFSET(CPU_FTR_L2CSR|CPU_FTR_CAN_NAP)
 1:
 	/* Go to NAP or DOZE now */
 	mfspr	r4,SPRN_HID0