* fix __force_inline for different GCC versions in cpp mode (the affected versions are different from c mode), and build kitchsink.c as a cpp file too for testing
* silly bug in host platform.h
* Platform updates
- Add PICO_RP2040=1 to rp2040 builds
- Add new PICO_RP2040_B0/1/2_SUPPORTED macros and retailer chip specific code to use
- Add doxygen to platform.h
- Make pico.h includable from assembly (because header order is important and tricky) - split out platform_asm.h
- Switch to using PICO_RP2040_B0_SUPPORTED in board headers
* add stdio_usb_connected() method
* add PICO_STDIO_USB_CONNECT_WAIT_TIMEOUT_MS to allow waiting for CDC connection during init(*
* add puts_raw and putchar_raw to skip any CR/LF translation
Fixes the following warning:
```
[...]/pico-sdk/src/host/hardware_divider/include/hardware/divider.h:81:26: warning: operand of ?: changes signedness from 'int' to 'uint32_t' {aka 'unsigned int'} due to unsignedness of other operand [-Wsign-compare]
return b ? (a / b) : -1;
^~
```
* remove broken and fairly pointless deep sleep API, use multicore_reset_core1 instead
* strict-prototype for multicore_fifo_drain() in host header
* Also for multicore_lockout_victim_init()
Co-authored-by: Luke Wren <wren6991@gmail.com>
