Revert "msm: ext-buck-support: add external buck support driver"

This reverts commit 571ca6fca5ff275bf39601166f8843e436b1853e.

Reason for revert:
This change is deviated from the msm-3.10 due to comments from
kernel approvers. To address later merge conflicts reverting the
change.

Change-Id: I574eda66aa0ad04434f7856dab5a56ea6aa7a4ab
Signed-off-by: Murali Nalajala <mnalajal@codeaurora.org>
3 files changed