remove usb middleware files

[jsiverskog]

these files are brought in from git@github.com:nxp-mcuxpresso/mcux-sdk-middleware-usb.git by west. let's remove them from this repository to lessen confusion.

Prerequisites

• [x] I have checked latest main branch and the issue still exists.
• [x] I did not see it is stated as known-issue in release notes.
• [x] No similar GitHub issue is related to this change.
• [x] My code follows the commit guidelines of this project.
• [x] I have performed a self-review of my own code.
• [] My changes generate no new warnings.
• [] I have added tests that prove my fix is effective or that my feature works.

Describe the pull request remove duplicate files

Type of change

• [x] cleanup

[danieldegrasse]

@mcuxsusan could you take a look at this PR?

[mcuxsusan]

Thanks @jsiverskog for the contribution, that's also what we are going to clean out from the mcux-sdk.