Ensure cam_frame_t structure is correctly aligned

[igrr]

From the discussion in esp-rs/esp-idf-sys#278 and esp-rs/rust#195:

In this line:

esp32-camera/driver/cam_hal.c

Line 268 in dba8da9

cam_obj->frames = (cam_frame_t *)heap_caps_calloc(1, cam_obj->frame_cnt * sizeof(cam_frame_t), MALLOC_CAP_DEFAULT);

we need to use heap_caps_aligned_calloc and request 8-byte alignment, since alignof(cam_frame_t) is 8 bytes.

(The code "works" as is, but would trigger UBSAN if it was enabled (-fsanitize=undefined) and is also resulting in the unaligned pointer error on Rust side, since the pointer returned by heap_caps_calloc may not meet the alignment requirements.)

[AxelLin]

Fixed by 8df17f7.

[github-actions]

This issue appears to be stale. Please close it if its no longer valid.