xtensa/esp32s3: fix esp32s3_cam uninit/stop_capture bugs

[JianyuWang0623]

Summary

Fix several issues in the ESP32-S3 CAM driver that cause heap corruption, IRQ mapping corruption, and stale DMA writes when using the camera example app with V4L2 USERPTR mode.

Changes

• stop_capture: reset DMA channel, CAM module and AFIFO under spinlock to fully quiesce hardware before returning. Clear pending VSYNC interrupt to prevent stale ISR firing.

• uninit: reset CAM/AFIFO before releasing DMA to prevent in-flight transfers after channel detach. Use esp_teardown_irq with correct peripheral ID (ESP32S3_PERIPH_LCD_CAM) instead of irq_detach which corrupts the shared IRQ mapping table. Mask interrupts and clear pending flags under spinlock before detaching handler.

• uninit: preserve XCLK output so the sensor remains accessible via I2C for subsequent re-initialization.

• set_buf/uninit: track driver-allocated vs user-provided frame buffers with fb_allocated flag to prevent double-free when using V4L2 USERPTR mode.

Impact

• Fixes crash (StoreProhibitedCause) in mm_delayfree during camera app cleanup
• Fixes IRQ 35 panic on second camera app invocation (irq_detach vs esp_teardown_irq)
• Prevents potential DMA writes to freed buffers after stop_capture

Testing

Tested on lckfb-szpi-esp32s3 (ESP32-S3 + GC0308 sensor):

• Camera example app: 10 captures + LCD preview + normal exit, no crash
• Multiple consecutive runs stable
• camcap (simple V4L2 capture) 3x consecutive pass
• ADB stable throughout

Related PR

apps-side fix: apache/nuttx-apps#3446