MIPS: Loongson64: Do not write the read only field LPA of CP0_CONFIG3

The field LPA of CP0_CONFIG3 register is read only for Loongson64, so the
write operations are meaningless, remove them.
Signed-off-by: NTiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/include/asm/mach-loongson64/kernel-entry-init.h

@@ -19,10 +19,6 @@
 	.macro	kernel_entry_setup
 	.set	push
 	.set	mips64
-	/* Set LPA on LOONGSON3 config3 */
-	mfc0	t0, CP0_CONFIG3
-	or	t0, (0x1 << 7)
-	mtc0	t0, CP0_CONFIG3
 	/* Set ELPA on LOONGSON3 pagegrain */
 	mfc0	t0, CP0_PAGEGRAIN
 	or	t0, (0x1 << 29)
@@ -54,10 +50,6 @@
 	.macro	smp_slave_setup
 	.set	push
 	.set	mips64
-	/* Set LPA on LOONGSON3 config3 */
-	mfc0	t0, CP0_CONFIG3
-	or	t0, (0x1 << 7)
-	mtc0	t0, CP0_CONFIG3
 	/* Set ELPA on LOONGSON3 pagegrain */
 	mfc0	t0, CP0_PAGEGRAIN
 	or	t0, (0x1 << 29)

arch/mips/loongson64/numa.c

@@ -39,9 +39,6 @@ static void enable_lpa(void)
 {
 	unsigned long value;
 
-	value = __read_32bit_c0_register($16, 3);
-	value |= 0x00000080;
-	__write_32bit_c0_register($16, 3, value);
 	value = __read_32bit_c0_register($16, 3);
 	pr_info("CP0_Config3: CP0 16.3 (0x%lx)\n", value);