KabylakeOpenBoardPkg/I2cHdmiDebugSerialPortLib: Configurable timings

Now that an implementation of the HDMI debug port is available at high
speed, make the timing parameters configurable. As this is
implementation, not board dependent, perhaps these could become
dynamic PCDs.

Arduino sketch available at
https://github.com/benjamindoron/i2c_debug_port

.

Tested on Adafruit ItsyBitsy M4, using 1 MHz clock and 60 us delay.

Cc: Sai Chaganty <rangasai.v.chaganty@intel.com>
Cc: Isaac Oram <isaac.w.oram@intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Chasel Chiu <chasel.chiu@intel.com>
Signed-off-by: Benjamin Doron <benjamin.doron00@gmail.com>
Reviewed-by: Isaac Oram <isaac.w.oram@intel.com>
Reviewed-by: Nate DeSimone <nathaniel.l.desimone@intel.com>