mmc: block: add missing header dependencies

We get 1 warning when building kernel with W=1:
drivers/mmc/card/block.c:2147:5: warning: no previous prototype for
'mmc_blk_issue_rq' [-Wmissing-prototypes]

In fact, this function is declared in drivers/mmc/card/block.h, so this
patch adds missing header dependencies.
Signed-off-by: NBaoyou Xie <baoyou.xie@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

drivers/mmc/card/block.c

@@ -46,6 +46,7 @@
 #include <asm/uaccess.h>
 
 #include "queue.h"
+#include "block.h"
 
 MODULE_ALIAS("mmc:block");
 #ifdef MODULE_PARAM_PREFIX