Tagging _start as a function

Change-Id: I09c91069422089edef9d3b5d497009104f76f435

springbok/crt0.S

diff --git a/springbok/crt0.S b/springbok/crt0.S
index c7514ee..822fac7 100644
--- a/springbok/crt0.S
+++ b/springbok/crt0.S
@@ -15,6 +15,7 @@
         .section .text._start
         .align 2
         .globl _start
+        .type _start, @function
 _start:
         ###############################################
         # Put all scalar registers into a known state #