Build enhancements

[nalajcie]

Description

• azure_sdk: remove unnecessary patches
  CFLAGS don't have coding-style flags now.
• dropbear: remove duplicate CFLAGS
• build: update for new LDFLAGS format
  LDFLAGS are now in gcc format (not ld format as previously)

CI to pass: phoenix-rtos/phoenix-rtos-project#823

Motivation and Context

CI-334

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

How Has This Been Tested?

• Already covered by automatic testing.
• New test added: (add PR link here).
• Tested by hand on: (list targets here).

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing linter checks and tests passed.
• My changes generate no new compilation warnings for any of the targets.

Special treatment

• This PR needs additional PRs to work (list the PRs, preferably in merge-order).
• I will merge this PR by myself when appropriate.

[github-actions]

Unit Test Results

2 782 tests  +4   2 512 ✔️ +4   9m 42s ⏱️ + 1m 43s
   131 suites +4      270 💤 ±0 
       1 files   ±0          0 ❌ ±0 

Results for commit d243d64. ± Comparison against base commit ef66802.

♻️ This comment has been updated with latest results.