[svdconv] changed casts to dynamic_cast (#1336)

[grasci-arm]

Changed casts to dynamic_cast<>() and added a pointer check where missing.
See https://github.com/Open-CMSIS-Pack/devtools/security/code-scanning/10396

[github-actions]

Test Results

 6 files  12 suites   0s ⏱️
28 tests 28 ✅ 0 💤 0 ❌
84 runs  84 ✅ 0 💤 0 ❌

Results for commit 0662c21.

[codecov]

Codecov Report

❌ Patch coverage is 5.40541% with 35 lines in your changes missing coverage. Please review.
✅ Project coverage is 66.77%. Comparing base (776aed9) to head (0662c21).
⚠️ Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
tools/svdconv/SVDModel/src/SvdCpu.cpp	0.00%	30 Missing ⚠️
tools/svdconv/SVDModel/src/SvdEnum.cpp	28.57%	0 Missing and 5 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2240      +/-   ##
==========================================
- Coverage   66.77%   66.77%   -0.01%     
==========================================
  Files         181      181              
  Lines       38711    38713       +2     
  Branches    22711    22715       +4     
==========================================
- Hits        25850    25849       -1     
- Misses       8078     8079       +1     
- Partials     4783     4785       +2     

Flag	Coverage Δ
svdconv-cov	40.73% <5.40%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
tools/svdconv/SVDModel/src/SvdEnum.cpp	45.67% <28.57%> (-0.91%)	⬇️
tools/svdconv/SVDModel/src/SvdCpu.cpp	40.16% <0.00%> (-0.17%)	⬇️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.