drm/vc4: hdmi: Rename drm_encoder pointer in mode_valid

The mode_valid hook on the encoder uses a pointer to a drm_encoder called
crtc, which is pretty confusing. Let's rename it to encoder to make it
clear what it is.
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Hoegeun Kwon <hoegeun.kwon@samsung.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://patchwork.freedesktop.org/patch/msgid/7fbabab03992efe4a3a3640ac5ee2bb49b1c7338.1599120059.git-series.maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_hdmi.c

@@ -556,7 +556,7 @@ static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
 }
 
 static enum drm_mode_status
-vc4_hdmi_encoder_mode_valid(struct drm_encoder *crtc,
+vc4_hdmi_encoder_mode_valid(struct drm_encoder *encoder,
 			    const struct drm_display_mode *mode)
 {
 	/*