mmc: core: change quirks.c to be a header file

Rename quirks.c to quirks.h, and include it for
individual C files which need it.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index a64a870..f092a55 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -23,6 +23,7 @@
 #include "card.h"
 #include "host.h"
 #include "bus.h"
+#include "quirks.h"
 #include "sd.h"
 #include "sdio_bus.h"
 #include "mmc_ops.h"