reusable-copyright-license-check.yml: Add root level license detection

[Tarun Goyal (targoy-qti)]

https://jira-dc.qualcomm.com/jira/browse/LOSTINTPRJ-2041
https://github.com/qualcomm/copyright-license-checker-action/releases/tag/v1.2.0

Overview

Enhance license detection to automatically scan repository LICENSE
files using the scancode toolkit, with intelligent fallback to
configuration-based lookup.

Key Changes

1. Automatic License Detection

• Added detect_license_from_file() function
• Scans LICENSE files using scancode toolkit
• Returns SPDX license identifiers
• Supports multiple formats:
  • LICENSE
  • LICENSE.txt
  • LICENSE.md
  • COPYING

2. Enhanced License Resolution Strategy

Implemented a three-tier fallback in get_license():

1. Primary: Auto-detect from repository LICENSE file
2. Fallback: Config-based lookup using repository name
3. Default: Return BSD-3-Clause-Clear

3. BSD License Normalization

• Normalize BSD variants:
  • BSD-2-Clause
  • BSD-3-Clause
  • LicenseRef-scancode-bsd-x11
• Map all variants to BSD-3-Clause-Clear
• Ensure case-insensitive normalization

Impact

• Reduce dependency on manual config maintenance
• Improve accuracy using repository source files
• Preserve backward compatibility

Benefits

• Automation: No manual license configuration needed
• Accuracy: Detect licenses from actual source files
• Consistency: Standardize BSD license handling