MIPS: don't use camel-case style

Replace camel-case style with upper-case style globally.

Signed-off-by: Zhizhou Zhang <etou.zh@gmail.com>
diff --git a/arch/mips/cpu/xburst/start.S b/arch/mips/cpu/xburst/start.S
index d846104..3a8280c 100644
--- a/arch/mips/cpu/xburst/start.S
+++ b/arch/mips/cpu/xburst/start.S
@@ -96,7 +96,7 @@
 	li	t0, KSEG0
 	addi	t1, t0, CONFIG_SYS_DCACHE_SIZE
 2:
-	cache	Index_Writeback_Inv_D, 0(t0)
+	cache	INDEX_WRITEBACK_INV_D, 0(t0)
 	bne	t0, t1, 2b
 	 addi	t0, CONFIG_SYS_CACHELINE_SIZE
 
@@ -106,7 +106,7 @@
 	li	t0, KSEG0
 	addi	t1, t0, CONFIG_SYS_ICACHE_SIZE
 3:
-	cache	Index_Invalidate_I, 0(t0)
+	cache	INDEX_INVALIDATE_I, 0(t0)
 	bne	t0, t1, 3b
 	 addi	t0, CONFIG_SYS_CACHELINE_SIZE