drm/exynos/decon5433: fix CMU programming

DECON_CMU register has reserved bits which should not be zeroed, otherwise
IP can behave strangely and cause IOMMU faults.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos5433_drm_decon.c

@@ -142,10 +142,6 @@ static void decon_commit(struct exynos_drm_crtc *crtc)
 		m->crtc_vsync_end = m->crtc_vsync_start + 1;
 	}
 
-	/* enable clock gate */
-	val = CMU_CLKGAGE_MODE_SFR_F | CMU_CLKGAGE_MODE_MEM_F;
-	writel(val, ctx->addr + DECON_CMU);
-
 	if (ctx->out_type & (IFTYPE_I80 | I80_HW_TRG))
 		decon_setup_trigger(ctx);