Goodix CTP controllers require AVDD28, VDDIO regulators for power-on
sequence.

The delay between these regualtor operations as per Power-on Timing
from datasheet[1] is 0 (T1 >= 0 usec).

So, enable and disable these regulators in proper order using normal
regulator functions without any delay in between.

[1] GT5663 Datasheet_English_20151106_Rev.01
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>