GitLab

Changes are:
- Remove include of stm32's adc.h because it was recently changed and is
  no longer compatible with teensy (and not used anyway).
- Remove define of __disable_irq in mpconfigport.h because it was clashing
  with an equivalent definition in core/mk20dx128.h.
- Add -Werror to CFLAGS, and change -std=gnu99 to -std=c99.
Signed-off-by: Damien George <damien@micropython.org>