Suppport for Py32L020

[garudaonekh]

https://github.com/OpenPuya/PY32L020_Firmware

Hi, please add support for this new low power series

[IOsetting]

I haven't bought PY32L020, but by comparing the register definitions, I would say F002B and L020 are the same chip.
Setting MCU_TYPE = PY32F002Bx5 will work on PY32L020

[garudaonekh]

Thanks, I will try it when I receive the sample. Somehow, it has DEEP STOP mode[ https://github.com/OpenPuya/PY32L020_Firmware/tree/master/Projects/PY32L020-STK/Example/PWR/PWR_DEEPSTOP_WFI ], which is 0.7ua

[IOsetting]

PY32F002B also supports DEEP STOP in my test, the test code is at Examples/PY32F002B/LL/PWR/PWR_DeepStop