mmc-utils: RPMB: add support for 4 rpmb operations

mmc rpmb write-key <rpmb device> <key file>
  Program authentication key which is 32 bytes length and stored in the specified file.
  Also you can specify '-' instead of key file path and utility will read the key from stdin.
  BEWARE: key can be programmed only once!
  Example:
    $ echo -n AAAABBBBCCCCDDDDEEEEFFFFGGGGHHHH | mmc rpmb write-key /dev/mmcblk0rpmb -

mmc rpmb read-counter <rpmb device>
  Counter value for the <rpmb device> will be read to stdout.

mmc rpmb read-block <rpmb device> <address> <blocks count> <output file> [key file]
  Blocks of 256 bytes will be read from <rpmb device> to output file or stdout if '-'
  is specified instead of regular path. If key is specified - read data will be verified.
  Instead of regular path you can specify '-' and key will be read from stdin.
  Example:
    $ echo -n AAAABBBBCCCCDDDDEEEEFFFFGGGGHHHH | \
        mmc rpmb read-block /dev/mmcblk0rpmb 0x02 2 /tmp/block -
  or read the block without verification
    $ mmc rpmb read-block /dev/mmcblk0rpmb 0x02 2 /tmp/block

mmc rpmb write-block <rpmb device> <address> <256 byte data file> <key file>
  Block of 256 bytes will be written from data file to <rpmb device>.
  Also you can specify '-' instead of key file path or data file and utility will read the
  data from stdin.
  Example:
    $ (awk 'BEGIN {while (c++<256) printf "a"}' | echo -n AAAABBBBCCCCDDDDEEEEFFFFGGGGHHHH) | \
      mmc rpmb write-block /dev/mmcblk0rpmb 0x02 - -

Signed-off-by: Roman Pen <r.peniaev@gmail.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>,
Cc: Ben Gardiner <bengardiner@nanometrics.ca>,
Signed-off-by: Chris Ball <chris@printf.net>
4 files changed