ARM: 8015/1: Add cpu_is_pj4 to distinguish PJ4 because it has some differences with V7

The patch add cpu_is_pj4 at arch/arm/include/asm/cputype.h
PJ4 has some differences with V7, for example the coprocessor.
To disinguish this kind of situation. cpu_is_pj4 is needed.
Signed-off-by: Chao Xie <chao.xie@marvell.com>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Matt Porter <mporter@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/cputype.h

@@ -221,4 +221,23 @@ static inline int cpu_is_xsc3(void)
 #define	cpu_is_xscale()	1
 #endif
 
+/*
+ * Marvell's PJ4 core is based on V7 version. It has some modification
+ * for coprocessor setting. For this reason, we need a way to distinguish
+ * it.
+ */
+#ifndef CONFIG_CPU_PJ4
+#define cpu_is_pj4()	0
+#else
+static inline int cpu_is_pj4(void)
+{
+	unsigned int id;
+
+	id = read_cpuid_id();
+	if ((id & 0xfffffff0) == 0x562f5840)
+		return 1;
+
+	return 0;
+}
+#endif
 #endif