arm: relocate_code() is no longer noreturn

Commit e05e5de7fae5bec79617e113916dac6631251156 made ARM's relocate_code()
return to its caller, but it did not update its declaration accordingly.

Fixing this function declaration fixes dropped C code following calls to
relocate_code().

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
diff --git a/arch/arm/cpu/sa1100/start.S b/arch/arm/cpu/sa1100/start.S
index 01d1a59..fbc2d35 100644
--- a/arch/arm/cpu/sa1100/start.S
+++ b/arch/arm/cpu/sa1100/start.S
@@ -143,9 +143,7 @@
 /*
  * void relocate_code (addr_sp, gd, addr_moni)
  *
- * This "function" does not return, instead it continues in RAM
- * after relocating the monitor code.
- *
+ * This function relocates the monitor code.
  */
 	.globl	relocate_code
 relocate_code: