Bump third_party/icestorm from `fa1c932` to `d9ea2e1`
Bump third_party/icestorm from `fa1c932` to `d9ea2e1`

Bumps [third_party/icestorm](https://github.com/cliffordwolf/icestorm) from `fa1c932` to `d9ea2e1`.
- [Release notes](https://github.com/cliffordwolf/icestorm/releases)
- [Commits](https://github.com/cliffordwolf/icestorm/compare/fa1c932452e8efe1dfcc6ff095e3f7130a7906b1...d9ea2e15fccebbbce59409b0ae7a1481d78aab86)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
SymbiFlow/symbiflow-arch-defs,SymbiFlow/symbiflow-arch-defs