input: sensors: modify initial distance when apds9930 enabled

There's an observed issue that the proximity value is near after
enable proximity sensor. Thus modify the logic to reflect the
actual distance.

CRs-fixed: 649445
Change-Id: I0747fa70b36ccedce0fd5748b3b0825e52f5e039
Signed-off-by: Oliver Wang <mengmeng@codeaurora.org>