gpu: ipu-v3: ipu-csi: Remove unused functions

gpu: ipu-v3: ipu-csi: Remove unused functions

ipu_csi_get_window(), ipu_csi_is_interlaced() and
ipu_csi_set_test_generator() were added in 2014 by
commit 2ffd48f2e7ae ("gpu: ipu-v3: Add Camera Sensor Interface unit")
but have remained unused.

Remove them.

ipu_csi_set_testgen_mclk() is now unused.

Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20241226022752.219399-7-linux@treblig.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>