input: sensor: add FIR filter for noise filtering

Add FIR filter to process light sensor data of stk3x1x ALPS. This
filter is used to suppress data jitter which is caused by power
supply noise.

CRs-Fixed: 524706
Change-Id: Ic3a33621dffc69f198f0389efcb82aa0963efd97
Signed-off-by: Bingzhe Cai <bingzhec@codeaurora.org>