armv7m: detect floating point feature

This patch add fp feature detection on cortex-m4.

Change-Id: I99e9d1bf5534630a22b8ad9c878165683db2d0ba
Signed-off-by: Mathias K <kesmtp@freenet.de>
Reviewed-on: http://openocd.zylin.com/524
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>

src/target/armv7m.h

@@ -97,6 +97,11 @@ enum {
 	ARMV7M_LAST_REG,
 };
 
+enum {
+	FP_NONE = 0,
+	FPv4_SP,
+};
+
 #define ARMV7M_COMMON_MAGIC 0x2A452A45
 
 struct armv7m_common {
@@ -108,6 +113,8 @@ struct armv7m_common {
 	int exception_number;
 	struct adiv5_dap dap;
 
+	int fp_feature;
+
 	uint32_t demcr;
 
 	/* Direct processor core register read and writes */