Import 'drm-ffi' crate

Request Document: go/android-rust-importing-crates
For CL Reviewers: go/android3p#cl-review
For Build Team: go/ab-third-party-imports
Bug: http://b/328179939
Test: m libdrm_ffi (with aosp/2997556 merged locally)

Change-Id: Id6ca48282ad7bd31d281e9e6652d3bcb8b511ba8

• .cargo_vcs_info.json[Added - diff]
• Android.bp[Added - diff]
• Cargo.toml[Added - diff]
• Cargo.toml.orig[Added - diff]
• LICENSE[Added - diff]
• METADATA[Added - diff]
• MODULE_LICENSE_MIT[Added - diff]
• OWNERS[Added - diff]
• cargo_embargo.json[Added - diff]
• src/gem.rs[Added - diff]
• src/ioctl.rs[Added - diff]
• src/lib.rs[Added - diff]
• src/mode.rs[Added - diff]
• src/syncobj.rs[Added - diff]
• src/utils.rs[Added - diff]