[ARM] 3064/1: start using ixp2000_reg_wrb

Patch from Lennert Buytenhek

Switch the users of ixp2000_reg_write that depend on writes being
flushed out of the write buffer by the time that function returns
over to ixp2000_reg_wrb.

When using XCB=101, writes to the same functional unit are still
guaranteed to complete in order, so we only need to protect against:
- reordering of writes to different functional units
- masking an interrupt and then reenabling the IRQ bit in CPSR

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-ixp2000/ixdp2x00.c b/arch/arm/mach-ixp2000/ixdp2x00.c
index 8b4a839..00af934 100644
--- a/arch/arm/mach-ixp2000/ixdp2x00.c
+++ b/arch/arm/mach-ixp2000/ixdp2x00.c
@@ -81,7 +81,7 @@
 
 	dummy = *board_irq_mask;
 	dummy |=  IXP2000_BOARD_IRQ_MASK(irq);
-	ixp2000_reg_write(board_irq_mask, dummy);
+	ixp2000_reg_wrb(board_irq_mask, dummy);
 
 #ifdef CONFIG_ARCH_IXDP2400
 	if (machine_is_ixdp2400())
@@ -101,7 +101,7 @@
 
 	dummy = *board_irq_mask;
 	dummy &=  ~IXP2000_BOARD_IRQ_MASK(irq);
-	ixp2000_reg_write(board_irq_mask, dummy);
+	ixp2000_reg_wrb(board_irq_mask, dummy);
 
 	if (machine_is_ixdp2400()) 
 		ixp2000_release_slowport(&old_cfg);