input: sensors: correct the output data reported by akm09911

The measurement data read from akm09911 should be adjusted as the
following equation: Hadj = H * (ASA/128 + 1), where Hadj is the
output data, H is the raw data from akm09911 registers and ASA is
the sensor sensitivity adjustment data.

Change-Id: I893427da6cb31352340f94184490899f2c417912
Signed-off-by: Oliver Wang <mengmeng@codeaurora.org>