drm/vc4: hdmi: Add PHY RNG enable / disable function

Let's continue the implementation of hooks for the parts that change in the
BCM2711 SoC with the PHY RNG setup.

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/216155f1c0b83e622ac60a2f7d00eb707de3acba.1599120059.git-series.maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_hdmi.h

@@ -47,6 +47,12 @@ struct vc4_hdmi_variant {
 
 	/* Callback to disable the PHY */
 	void (*phy_disable)(struct vc4_hdmi *vc4_hdmi);
+
+	/* Callback to enable the RNG in the PHY */
+	void (*phy_rng_enable)(struct vc4_hdmi *vc4_hdmi);
+
+	/* Callback to disable the RNG in the PHY */
+	void (*phy_rng_disable)(struct vc4_hdmi *vc4_hdmi);
 };
 
 /* HDMI audio information */
@@ -107,5 +113,7 @@ encoder_to_vc4_hdmi(struct drm_encoder *encoder)
 void vc4_hdmi_phy_init(struct vc4_hdmi *vc4_hdmi,
 		       struct drm_display_mode *mode);
 void vc4_hdmi_phy_disable(struct vc4_hdmi *vc4_hdmi);
+void vc4_hdmi_phy_rng_enable(struct vc4_hdmi *vc4_hdmi);
+void vc4_hdmi_phy_rng_disable(struct vc4_hdmi *vc4_hdmi);
 
 #endif /* _VC4_HDMI_H_ */