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

Some bootloaders are disabling write buffer coalescing. Enable it back
under linux.

Signed-off-by: Arnaud Patard <[e-mail]>
Signed-off-by: Russell King <[e-mail]>

arch/arm/mm/proc-xscale.S

···
  * 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
 
 /*