input: touchscreen: bu21150: write to AFE at early resume

The AFE spec requires a 70ms delay between the two writes to the same
AFE register. Previous implementation separates the two writes in
frame buffer early resume callback and frame buffer normal resume
callback, with the assumption that the gap between the two callbacks
is longer than 70ms, which may not be reliable. Add explicit delay of
70ms to guarantee the correct timing sequence.

Change-Id: Ia1ebdaa6e61ffd954794a45cbe6b0524088e17e1
Signed-off-by: Jing Lin <jinglin@codeaurora.org>
Signed-off-by: Bharat Pawar <bpawar@codeaurora.org>