esp8266/uart: Move a few functions from iRAM to iROM.
esp8266/uart: Move a few functions from iRAM to iROM.

They call functions in iROM so do not need to be in iRAM.

pramasoul/micropython,pramasoul/micropython,bvernoux/micropython,pramasoul/micropython,selste/micropython,kerneltask/micropython,selste/micropython,bvernoux/micropython,tobbad/micropython,tobbad/micropython,henriknelson/micropython,henriknelson/micropython,adafruit/circuitpython,kerneltask/micropython,tobbad/micropython,bvernoux/micropython,kerneltask/micropython,pramasoul/micropython,adafruit/circuitpython,adafruit/circuitpython,selste/micropython,tobbad/micropython,bvernoux/micropython,kerneltask/micropython,bvernoux/micropython,selste/micropython,selste/micropython,MrSurly/micropython,MrSurly/micropython,kerneltask/micropython,MrSurly/micropython,MrSurly/micropython,tobbad/micropython,adafruit/circuitpython,henriknelson/micropython,pramasoul/micropython,adafruit/circuitpython,henriknelson/micropython,henriknelson/micropython,adafruit/circuitpython,MrSurly/micropython