drm: mali-dp: Remove mclk rate management

The rate of mclk depends on the use-case. If no downscaling is required,
then mclk == pxlclk is a valid option; with downscaling however, the
rate at which mclk runs determines how much a plane can be downscaled
before composition. This is a system integration + power management
issue that is more suited to firmware rather than this driver.

Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>

drivers/gpu/drm/arm/malidp_crtc.c

@@ -63,8 +63,7 @@ static void malidp_crtc_enable(struct drm_crtc *crtc)
 
 	clk_prepare_enable(hwdev->pxlclk);
 
-	/* mclk needs to be set to the same or higher rate than pxlclk */
-	clk_set_rate(hwdev->mclk, crtc->state->adjusted_mode.crtc_clock * 1000);
+	/* We rely on firmware to set mclk to a sensible level. */
 	clk_set_rate(hwdev->pxlclk, crtc->state->adjusted_mode.crtc_clock * 1000);
 
 	hwdev->modeset(hwdev, &vm);