APPRO 8x GMSL camera issues

[taichichen]

Fix 4 issues found during APPRO 8x GMSL camera testing on PTL platform:

1. fix stop hang graceful pollerr - Fix camera stop hanging due to POLLERR not handled gracefully
2. Fix 8x camera concurrent stream on - Fix concurrent streaming for 8 cameras
3. Fix sensor name parse error - Fix sensor name parsing when multiple cameras are connected
4. Fix 2nd time open 8x gmsl camera with mmap streaming fail - Fix failure when reopening cameras with mmap streaming

Tested with 8x ISX031 GMSL cameras — all open/close sequences pass reliably.

[taichichen]

verify issue with ipu7-camera-hal, main branch , commit 24d8923695dd977784845b637aba2cc21a927810
it pass.
Drop the PR>