Use the same name (lowlevel_init) for all (ARM) boards

cpu/at91rm9200/lowlevel.S

@@ -74,8 +74,8 @@ _MTEXT_BASE:
 	.word	TEXT_BASE
 #endif
 
-.globl lowlevelinit
-lowlevelinit:
+.globl lowlevel_init
+lowlevel_init:
 	/* Get the CKGR Base Address */
 	ldr     r1, =AT91C_BASE_CKGR
 	/* Main oscillator Enable register */

cpu/at91rm9200/start.S

@@ -124,9 +124,9 @@ reset:
 /****	mov     sp, r1			****/
 	/*
 	 * This does a lot more than just set up the memory, which
-	 * is why it's called lowlevelinit
+	 * is why it's called lowlevel_init
 	 */
-	bl	lowlevelinit /* in lowlevel.S */
+	bl	lowlevel_init /* in lowlevel.S */
 
 	/*
 	 * Read/modify/write CP15 control register