During kernel boot, it will try to read some logical sectors
of each block device node for the possible partition table.

But since RPMB partition is special and can not be accessed
by normal eMMC read / write CMDs, it will cause below error
messages during kernel boot:
...
 mmc0: Got data interrupt 0x00000002 even though no data operation was in progress.
 mmcblk0rpmb: error -110 transferring data, sector 0, nr 32, cmd response 0x900, card status 0xb00
 mmcblk0rpmb: retrying using single block read
 mmcblk0rpmb: timed out sending r/w cmd command, card status 0x400900
 mmcblk0rpmb: timed out sending r/w cmd command, card status 0x400900
 mmcblk0rpmb: timed out sending r/w cmd command, card status 0x400900
 mmcblk0rpmb: timed out sending r/w cmd command, card status 0x400900
 mmcblk0rpmb: timed out sending r/w cmd command, card status 0x400900
 mmcblk0rpmb: timed out sending r/w cmd command, card status 0x400900
 end_request: I/O error, dev mmcblk0rpmb, sector 0
 Buffer I/O error on device mmcblk0rpmb, logical block 0
 end_request: I/O error, dev mmcblk0rpmb, sector 8
 Buffer I/O error on device mmcblk0rpmb, logical block 1
 end_request: I/O error, dev mmcblk0rpmb, sector 16
 Buffer I/O error on device mmcblk0rpmb, logical block 2
 end_request: I/O error, dev mmcblk0rpmb, sector 24
 Buffer I/O error on device mmcblk0rpmb, logical block 3
...

This patch will discard the access request in eMMC queue if
it is RPMB partition access request. By this way, it avoids
trigger above error messages.

Fixes: 090d25fe ("mmc: core: Expose access to RPMB partition")
Signed-off-by: Yunpeng Gao <yunpeng.gao@intel.com>
Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
Tested-by: Michael Shigorin <mike@altlinux.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>