mmc: block: Change MMC_IOC_MAX_BYTES

It is used for limitation of buffer size during IOCTL such as FFU.
However, eMMC FW size is bigger than (512L*256).
(For instance, currently, Samsung eMMC FW size is over 300KB.)
So, it needs to increase to execute FFU.

Signed-off-by: Jeonghan Kim <jh4u.kim@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

include/uapi/linux/mmc/ioctl.h

@@ -69,6 +69,6 @@ struct mmc_ioc_multi_cmd {
  * is enforced per ioctl call.  For larger data transfers, use the normal
  * block device operations.
  */
-#define MMC_IOC_MAX_BYTES  (512L * 256)
+#define MMC_IOC_MAX_BYTES  (512L * 1024)
 #define MMC_IOC_MAX_CMDS    255
 #endif /* LINUX_MMC_IOCTL_H */