socfpga: boot0 hook: adjust to unified boot0 semantics

With the updated boot0 semantics (i.e. giving the boot0-hook control
over when and where the vector table is emitted), the boot0-hook for
the socfpga needs to be adjusted.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
diff --git a/arch/arm/mach-socfpga/include/mach/boot0.h b/arch/arm/mach-socfpga/include/mach/boot0.h
index 22d9e7f..d6b9435 100644
--- a/arch/arm/mach-socfpga/include/mach/boot0.h
+++ b/arch/arm/mach-socfpga/include/mach/boot0.h
@@ -7,6 +7,9 @@
 #ifndef __BOOT0_H
 #define __BOOT0_H
 
+_start:
+	ARM_VECTORS
+
 #ifdef CONFIG_SPL_BUILD
 	.balignl 64,0xf33db33f;