Revert ARM Scheduler Model: Add resources instructions, map resources

This reverts commit r177968. It is causing failures in a local build bot.

"fatal error: error in backend: Expected a variant SchedClass"

Original commit message:
Move the CortexA9 resources into the CortexA9 SchedModel namespace. Define
resource mappings under the CortexA9 SchedModel. Define resources and mappings
for the SwiftModel.