input: sensors: avoid frequent set/reset operation for mmc3416x

The set/reset operation takes long time to complete. This will
lead to the reported data can't streaming at high rate. Thus
change the logic to avoid freqent set/reset operation.

Change-Id: I2205eae31110348f312386214fb6e75dc4a15175
Signed-off-by: Oliver Wang <mengmeng@codeaurora.org>