drm/bridge: Remove redundant i2c_client in anx7625/it6505

These two drivers embed a i2c_client in their private driver data, but
only strict device is actually needed. Replace the i2c_client reference
with a struct device one.

Signed-off-by: Pin-yen Lin <treapking@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230718110407.1005200-1-wenst@chromium.org