Support embassy-usb on ESP32-S2 and ESP32-S3

[Dominaezzz]

Whilst this crate supports usb-device (which is not async), it'd be really cool if it also supported the async embassy-usb.

Some efforts have begun here.

[Dominaezzz]

These registers should be accessible by index. The 0 at the end can vary from 0 to 6.

pub type DOEPCTL0 = crate::Reg<doepctl0::DOEPCTL0_SPEC>;
pub type DOEPINT0 = crate::Reg<doepint0::DOEPINT0_SPEC>;
pub type DOEPTSIZ0 = crate::Reg<doeptsiz0::DOEPTSIZ0_SPEC>;
pub type DOEPDMA0 = crate::Reg<doepdma0::DOEPDMA0_SPEC>;
pub type DOEPDMAB0 = crate::Reg<doepdmab0::DOEPDMAB0_SPEC>;

[bjoernQ]

Probably the PACs should get patched to collect these registers into arrays. We use https://github.com/rust-embedded/svdtools for patching SVDs in https://github.com/esp-rs/esp-pacs