Better support multiple controllers configuration

[hathach]

Describe the PR

• Enhance configuration for multiple controllers e.g port0 for device, port1 for host and/or allow dynamic switching device/host role (not fully implemented yet). Previously CFG_TUSB_RHPORTx_MODE is used to fix device/host support.
• CFG_TUD_ENABLED/CFG_TUH_ENABLED and CFG_TUD_MAX_SPEED/CFG_TUH_MAX_SPEED can now be used instead of CFG_TUSB_RHPORTx_MODE
• tud_init(rhport), tuh_init(rhport) is used explicitly instead of tusb_init()
• backward compatible, everything that works previously, still work without any changes.