[MIPS] Fix build errors related to wbflush.h on tx4927/tx4938.

TX49 CPUs have a SYNC instruction so that CONFIG_CPU_HAS_WB is no
longer needed.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/tx4927/common/tx4927_setup.c

@@ -53,19 +53,9 @@ void __init tx4927_time_init(void);
 void dump_cp0(char *key);
 
 
-void (*__wbflush) (void);
-
-static void tx4927_write_buffer_flush(void)
-{
-	__asm__ __volatile__
-	    ("sync\n\t" "nop\n\t" "loop: bc0f loop\n\t" "nop\n\t");
-}
-
-
 void __init plat_mem_setup(void)
 {
 	board_time_init = tx4927_time_init;
-	__wbflush = tx4927_write_buffer_flush;
 
 #ifdef CONFIG_TOSHIBA_RBTX4927
 	{

arch/mips/tx4927/toshiba_rbtx4927/toshiba_rbtx4927_irq.c

@@ -129,6 +129,7 @@ JP7 is not bus master -- do NOT use -- only 4 pci bus master's allowed -- SouthB
 #include <asm/processor.h>
 #include <asm/reboot.h>
 #include <asm/time.h>
+#include <asm/wbflush.h>
 #include <linux/bootmem.h>
 #include <linux/blkdev.h>
 #ifdef CONFIG_RTC_DS1742

arch/mips/tx4938/common/irq.c

@@ -30,6 +30,7 @@
 #include <asm/irq.h>
 #include <asm/mipsregs.h>
 #include <asm/system.h>
+#include <asm/wbflush.h>
 #include <asm/tx4938/rbtx4938.h>
 
 /**********************************************************************************/

arch/mips/tx4938/common/setup.c

@@ -41,29 +41,10 @@ void __init tx4938_setup(void);
 void __init tx4938_time_init(void);
 void dump_cp0(char *key);
 
-void (*__wbflush) (void);
-
-static void
-tx4938_write_buffer_flush(void)
-{
-	mmiowb();
-
-	__asm__ __volatile__(
-		".set	push\n\t"
-		".set	noreorder\n\t"
-		"lw	$0,%0\n\t"
-		"nop\n\t"
-		".set	pop"
-		: /* no output */
-		: "m" (*(int *)KSEG1)
-		: "memory");
-}
-
 void __init
 plat_mem_setup(void)
 {
 	board_time_init = tx4938_time_init;
-	__wbflush = tx4938_write_buffer_flush;
 	toshiba_rbtx4938_setup();
 }
 

arch/mips/tx4938/toshiba_rbtx4938/irq.c

@@ -83,6 +83,7 @@ IRQ  Device
 #include <asm/processor.h>
 #include <asm/reboot.h>
 #include <asm/time.h>
+#include <asm/wbflush.h>
 #include <linux/bootmem.h>
 #include <asm/tx4938/rbtx4938.h>