imxrt needs to support generic CRC\SHA256 traits

[jerrysxie]

imxrt have hardware accelerator for CRC and SHA256. We should define a MCU agnostic interface for it so application does not need to hard link against embassy-imxrt.

platform-service has hard link to embassy-imxrt to access this functionality. We should replace these with generic traits: https://github.com/OpenDevicePartnership/embedded-services/blob/865bfd434d9458bee5182982b8f71a273db8ecae/platform-service/src/imxrt/embedded_crc.rs#L20

[felipebalbi]

RNG already implements generic RngCore trait:

https://github.com/OpenDevicePartnership/embassy-imxrt/blob/main/src/rng.rs#L206-L227

[jerrysxie]

RNG already implements generic RngCore trait:

https://github.com/OpenDevicePartnership/embassy-imxrt/blob/main/src/rng.rs#L206-L227

Great, remove RNG as it is already covered.