Revert "msm: add default enable mode option for lpm levels"

This reverts commit b774cded.
Change is no more needed as 8939 boots with all low power modes
enabled by default.

Change-Id: Ia70c0f1974c01086ea18bba8015925528bdd4c48
Signed-off-by: Venkat Devarasetty <vdevaras@codeaurora.org>