adc_key: delete early_suspend code [1/1]

adc_key: delete early_suspend code [1/1]

PD#OTT-144

Problem:
after the dark screen, the adc button does not work

Solution:
The adc_keypad introduces earlysuspend for MID project:
after the LCD backlight disable, prevent the user from
pressing the key to open some applications and not complete standby.
Now check the adc button using the "system_freezable_wq" system queue,
which replaces the function of the code.So can remove it.

Verify:
g12b socket

Change-Id: I2333ba3dc406d2624962d116293a0b9d36f97534
Signed-off-by: Yingyuan Zhu <yingyuan.zhu@amlogic.com>