When L1 cache is suppose to be lost, it needs to be cleaned before
entrering to the low power mode.

While at this, also fix few comments and remove un-necessary
clean_l2 lable.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>