Function pinGetKey replaced with pinValid.
Updated classes derived from UartBase.
Removed TER register setup to ensure compatibility with peripheral layout
of latest devices. TER register is initialized b default and used only
for software flow control.
Updated LPC43xx system functions.
Updated LPC43xx platform definitions.
Added UARTs. Fixed base clock domain address.
Updated pin functions for LPC43xx.
Added UartBase class for LPC43xx.