LPC4330_M4 port_api, us_ticker update

Corrects reported issues with port_api and us_ticker HAL drivers on LPC4330_M4 platform. A lookup table was implemented to support the port_pin() API. This mapping is required since the LPC43xx GPIO pin name is not the same as the MCU pin name. For example, GPIO3[7] uses pin P6_11, not P3_7.