[HAL][LPC176x] Pull out framework into separate repository

Framework and build platform now located at https://github.com/p3p/pio-framework-arduino-lpc176x and https://github.com/p3p/pio-nxplpc-arduino-lpc176x respectively

fix mkssbase leds

move hardware serial

remove hardware/software serial

Hardware Serial extraction

HardwareSerial ISRs

fix disabled serial2 causing Serial object to link

move usb devices out to framework

separate out adc/pwm peripheral function from hal.cpp

fix includes

remove unused pwm init

move adc

HAL header update

templated filtered adc

LPC1769 platform