mmc: Revert all packing related patches

The version of packing support excepted by the linux community is
slightly different from the one that was merged. This revert is needed
in order to upload the latest version from the linux community.

This patch reverts the following commits:
1.mmc: card: Add eMMC4.5 write packed commands unit-tests
  commit:  9b54d88c
2.mmc: card: Fix packing control enabling algorithm
  commit: e2ecb58a
3.mmc: block: Add MMC write packing statistics
  commit: e544d700
4.mmc: msm_sdcc: enable the write packing control
  commit: 8afe8d2a
5.mmc: msm_sdcc: Enable write packing capability
  commit: 25e2261a
6.mmc: block: Add write packing control
  commit: 63c61d6d
7.mmc: core: Support packed write command for eMMC4.5 device
  commit: 968c774e
8.mmc: core: Add packed command feature of eMMC4.5
  commit: 516994ee.

Change-Id: I8d5a3a2d035e66d81a6e32c4fecc65ea8f87865c
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>