drm/sun4i: Set TCON clock inside sun4i_tconX_mode_set

Currently we are configuring the TCON's dot clock or special clock
directly from the encoder mode_set functions. Since we already
provide mode_set helper functions for the TCON's 2 channels, we
can set the respective clock from those helpers, and reduce the
exposure of the TCON's internals.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

drivers/gpu/drm/sun4i/sun4i_tv.c

@@ -486,8 +486,6 @@ static void sun4i_tv_mode_set(struct drm_encoder *encoder,
 		      SUN4I_TVE_RESYNC_FIELD : 0));
 
 	regmap_write(tv->regs, SUN4I_TVE_SLAVE_REG, 0);
-
-	clk_set_rate(tcon->sclk1, mode->crtc_clock * 1000);
 }
 
 static struct drm_encoder_helper_funcs sun4i_tv_helper_funcs = {