msm: add default enable mode option for lpm levels

With cluster architecture changes all lpm modes are
enabled at boot. There are crashes at boot when all
lpms are enabled at boot. Add an option to enable
only selected modes at boot up.

Change-Id: Iebeab667aad8d12926b7a3a92deb8ca47c68bfb3
Signed-off-by: Venkat Devarasetty <vdevaras@codeaurora.org>