bootcounter_ram: Flush dcache after data is written into SDRAM

This patch adds a call to flush_dcache_range() to bootcount_store() to
make sure, that the bootcounter data (including the patterns) is
written to memory. Without this, platforms with dcache enabled may not
have the bootcounter updated upon reset.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Valentin Longchamp <valentin.longchamp@keymile.com>
diff --git a/drivers/bootcount/bootcount_ram.c b/drivers/bootcount/bootcount_ram.c
index 5bdabcd..e0d2669 100644
--- a/drivers/bootcount/bootcount_ram.c
+++ b/drivers/bootcount/bootcount_ram.c
@@ -35,6 +35,9 @@
 		writel(patterns[i % NBR_OF_PATTERNS],
 			&save_addr[i + OFFS_PATTERN]);
 
+	/* Make sure the data is written to RAM */
+	flush_dcache_range((ulong)&save_addr[0],
+			   (ulong)&save_addr[REPEAT_PATTERN + OFFS_PATTERN]);
 }
 
 ulong bootcount_load(void)