[ARM] 4864/1: Enable write buffer coalescing on IOP

Some bootloaders are disabling write buffer coalescing. Enable it back
under linux.
Signed-off-by: NArnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/proc-xscale.S

@@ -114,6 +114,10 @@ clean_addr:	.word	CLEAN_ADDR
  * Nothing too exciting at the moment
  */
 ENTRY(cpu_xscale_proc_init)
+	@ enable write buffer coalescing. Some bootloader disable it
+	mrc	p15, 0, r1, c1, c0, 1
+	bic	r1, r1, #1
+	mcr	p15, 0, r1, c1, c0, 1
 	mov	pc, lr
 
 /*