armv7m: cache: add flush & invalidate all dcache

Add functionality to flush & invalidate all the dcache using the
prototype declared in common header file.

Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
[trini: Add dummy functions for the not-enabled case]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/cpu/armv7m/cache.c b/arch/arm/cpu/armv7m/cache.c
index 162cfe3..e8f8642 100644
--- a/arch/arm/cpu/armv7m/cache.c
+++ b/arch/arm/cpu/armv7m/cache.c
@@ -253,6 +253,21 @@
 		return;
 	}
 }
+void flush_dcache_all(void)
+{
+	if (action_dcache_all(FLUSH_SET_WAY)) {
+		printf("ERR: D-cache not flushed\n");
+		return;
+	}
+}
+
+void invalidate_dcache_all(void)
+{
+	if (action_dcache_all(INVALIDATE_SET_WAY)) {
+		printf("ERR: D-cache not invalidated\n");
+		return;
+	}
+}
 #else
 void dcache_enable(void)
 {
@@ -268,6 +283,14 @@
 {
 	return 0;
 }
+
+void flush_dcache_all(void)
+{
+}
+
+void invalidate_dcache_all(void)
+{
+}
 #endif
 
 #ifndef CONFIG_SYS_ICACHE_OFF