clk: qcom: gcc-msm8998: Mark gpu_cfg_ahb_clk as critical

The GPU IOMMU depends on this clock and the hypervisor will crash
the SoC if this clock gets disabled because the secure contexts
that have been set on this IOMMU by the bootloader will become
unaccessible (or they get reset).
Mark this clock as critical to avoid this issue when the Adreno
GPU is enabled.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Link: https://lore.kernel.org/r/20210114221059.483390-6-angelogioacchino.delregno@somainline.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/qcom/gcc-msm8998.c

@@ -2081,6 +2081,12 @@ static struct clk_branch gcc_gpu_cfg_ahb_clk = {
 		.hw.init = &(struct clk_init_data){
 			.name = "gcc_gpu_cfg_ahb_clk",
 			.ops = &clk_branch2_ops,
+			/*
+			 * The GPU IOMMU depends on this clock and hypervisor
+			 * will crash the SoC if this clock goes down, due to
+			 * secure contexts protection.
+			 */
+			.flags = CLK_IS_CRITICAL,
 		},
 	},
 };