mmc: sdhci-msm: remove support for Qualcomm chipsets

The upstream sdhci-msm driver has diverged, removing the upstream version
to recreate our internal tree from msm-3.18 to msm-4.4.

Change-Id: I952b08667177272fdc30fea79b445f96a3fc2182
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
[xiaonian@codeaurora.org: fix trivial merge conflict]
Signed-off-by: Xiaonian Wang <xiaonian@codeaurora.org>