build(deps): bump cortex-m from 0.6.2 to 0.6.3

Bumps [cortex-m](https://github.com/rust-embedded/cortex-m) from 0.6.2 to 0.6.3.
- [Release notes](https://github.com/rust-embedded/cortex-m/releases)
- [Changelog](https://github.com/rust-embedded/cortex-m/blob/v0.6.3/CHANGELOG.md)
- [Commits](https://github.com/rust-embedded/cortex-m/compare/v0.6.2...v0.6.3)

Signed-off-by: dependabot[bot] <support@github.com>

Cargo.lock

@@ -60,6 +60,12 @@ version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a165d606cf084741d4ac3a28fb6e9b1eb0bd31f6cd999098cfddb0b2ab381dc0"
 
+[[package]]
+name = "bitfield"
+version = "0.13.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "46afbd2983a5d5a7bd740ccb198caf5b82f45c40c09c0eed36052d91cb92e719"
+
 [[package]]
 name = "bitflags"
 version = "1.2.1"
@@ -95,12 +101,13 @@ checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 
 [[package]]
 name = "cortex-m"
-version = "0.6.2"
+version = "0.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2954942fbbdd49996704e6f048ce57567c3e1a4e2dc59b41ae9fde06a01fc763"
+checksum = "2be99930c99669a74d986f7fd2162085498b322e6daae8ef63a97cc9ac1dc73c"
 dependencies = [
  "aligned",
  "bare-metal",
+ "bitfield",
  "volatile-register",
 ]