The machine_i2c_type, machine_spi_type and machine_timer_type symbols are
already declared in extmod/modmachine.h and should not be declared anywhere
else.
Also move declarations of machine_pin_type and machine_rtc_type to the
common header in extmod.
Signed-off-by: Damien George <damien@micropython.org>
This required to add two functions down the stack to uart.c and ra.sci.c.
- One for telling, whther the transmission is busy.
- One for reporting the size of the TX buffer.
Tested with a EK-RA6M2 board.