power: qpnp-fg: dont reschedule upon property read

The current code cancels and reschedules the work to update FG
properties. This could lead to delays if there is a constant
read of properties.

Remove that cancel and reschedule, which guarantees that the properties
could be at most 30 seconds old.

Change-Id: I836155ac58b350e72a919767331732a493191787
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>