* Make ExtUI respect MAXTEMP limits
  - Temperatures are now clamped by MAXTEMP limits rather than arbitrary values.
* Speed up USB init, add status
  - Speed up USB initialization
  - Show status message if init failed
* Enable status messages for EXTENSIBLE_UI
* Adjust max limit to MAX_TEMP - 15
* Misc. tweaks to formatting, const, etc.

* Remove duplicate calls to PrepareSector

Some flash memory API calls require that a call to `PrepareSector` is done before use. However this call is already made by the LPC1768 framework so the calls in this code are not required.

* Ensure correct alignment of RAM buffer

The LPC176X flash API requires that the RAM buffer used for write operations must be word-aligned. This change ensures that this is the case.

* Make CardReader a static class
* Make CardReader flags into bitfields

- In reference to #12166

* Apply #pragma once in headers
* Adjust some thermistors formatting
* Misc cleanup and formatting

* Add traceback after watchdog timeout

Add the cpability to perform a traceback following a watchdog timeout.

* Enhanced hardware SPI

Allow use of either SSP0 or SSP1.
Ensure that no data is left in I/O buffers after calls to enable sharing of SSP hardware.

* Make flash emulation of eeprom the default

Make use of flash for eeprom storage the default. This means that usage of eeprom will not cause USB drive mount/unmount operations.

* Allow sharing of SD card

SD card I/O operations from the USB stack take place in idle loop, rather than at interrupt time. Allowing sharing of the SPI bus.

New configuration options to allow usage of the SD card to be specified.

* Fix problem with hardware SPI pins

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

With default config and `EEPROM_SETTINGS`, saves over 200 bytes of PROGMEM.

Use a sector of the LPC flash memory to emulate EEPROM storage, removing the need to have an SD card to store system parameters.

- Clean up the API to use a `static` class instance to adhere to Marlin convention
- Add `const` position data access for read/write
- Add Storage capacity to the interface

The current Marlin implementation relies on a timer interrupt to start the ADC conversion and read it. However in some circumstances the interrupt can be delayed resulting in insufficient time being available for the ADC conversion. This results in a bad reading and false temperature fluctuations. These changes make sure that the conversion is complete (by checking the ADC hardware via the HAL) before reading a value.

See: https://github.com/MarlinFirmware/Marlin/issues/11323

Enable the endstop interrupts feature for LPC176x boards. Although Smoothieboard chose to use non-interrupt capable pins for their endstops, and this has been copied by clones, so they can't use it.