ARM: Add ARMv7-M support

Signed-off-by: Kamil Lulko <rev13@wp.pl>
diff --git a/arch/arm/cpu/armv7m/start.S b/arch/arm/cpu/armv7m/start.S
new file mode 100644
index 0000000..e05e984
--- /dev/null
+++ b/arch/arm/cpu/armv7m/start.S
@@ -0,0 +1,15 @@
+/*
+ * (C) Copyright 2015
+ * Kamil Lulko, <rev13@wp.pl>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+.globl	reset
+.type reset, %function
+reset:
+	b	_main
+
+.globl	c_runtime_cpu_setup
+c_runtime_cpu_setup:
+	mov	pc, lr