input: touchscreen: bu21150: pull-down AFE RST2 line in suspend

AFE driver needs to pull-down RST2 line in suspend. This takes over
operation from HAL library to kernel driver to avoid display not
coming up in resume.

Change-Id: I8215e9612e15896ec4dfab3883ed567c2a8a837a
Signed-off-by: Chun Zhang <chunz@codeaurora.org>