sh: Implement a default flush_dcache_all

Implement a weak default version of flush_dcache_all which is based on
the ARM default, which is to flush the entire range via
flush_dcache_range(...).

Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Tom Rini <trini@konsulko.com>

arch/sh/cpu/sh4/cache.c

@@ -65,6 +65,15 @@ void flush_dcache_range(unsigned long start, unsigned long end)
 	}
 }
 
+/*
+ * Default implementation:
+ * do a range flush for the entire range
+ */
+void flush_dcache_all(void)
+{
+	flush_dcache_range(0, ~0);
+}
+
 void invalidate_dcache_range(unsigned long start, unsigned long end)
 {
 	u32 v;