extmod/modmachine: Clean up decls of machine types to use common ones.

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>

ports/renesas-ra/boards/ra_pin_prefix.c

@@ -4,6 +4,7 @@
 
 #include "py/obj.h"
 #include "py/mphal.h"
+#include "extmod/modmachine.h"
 #include "pin.h"
 
 #define PIN_AD(p_name, p_pin, ad_bit, ad_channel) \