Input: ft5x06_ts: coding style and typo fixes

The change was made with reference to commit:
https://android.googlesource.com/kernel/msm/+/android-msm-hammerhead-3.4-kk-r1/drivers/input/touchscreen/ft5x06_ts.c



Signed-off-by: Guodong Xu <guodong.xu@linaro.org>