sh4: cache: correct flush_cache() to writeback and invalidate

In common usecases flush_cache() assumes both cache invalidation and
write-back to memory, instead of doing cache invalidation only with
the wrapped 'ocbi' instruction pin flush_cache() to cache invalidation
with memory write-back done by 'ocbp'.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/sh/cpu/sh4/cpu.c

@@ -37,7 +37,7 @@ int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 
 void flush_cache (unsigned long addr, unsigned long size)
 {
-	invalidate_dcache_range(addr , addr + size);
+	flush_dcache_range(addr , addr + size);
 }
 
 void icache_enable (void)