Support max3421e (usb host shield) for nrf52 and samd21/samd51

[hathach]

• Added max3421e (usb host shield) controller
• tested with nrf52 and samd21/samd51, work relatively well, there is a few hipcups, but it is due to tinyusb core (connection debouncing issue, will fix later)
• update all DualRole examples: CDC/serial_host_bridge, Simple/device_info, MassStorage/msc_file_explorer, HID/hid_device_report. Tested all feather nrf52840, metro m0 & m4 express, all seems to work well.
• Fix MSC host wait_for_io() issue when running with freeRTOS (e.g nrf52840).

PS: not tested with hub + device, hub + lowspeed device

[lyusupov]

I am curious of why external MAX3421 USB Host is required for a SAMD x1 SoC when the latter can do the Host feature with built-in hardware components ?
Please, see this library as a known good example: https://github.com/gdsports/USB_Host_Library_SAMD

[hathach]

we like to keep usb device for uploading and debugging. Feel free to use other library if you don't want to use max3421 for samd