imx8m: clock: improve irq response latency

Improve the IRQ response latency by setting GIC root clock source to
sys_pll2_200m from osc.

Signed-off-by: Peng Fan <peng.fan@nxp.com>

arch/arm/mach-imx/imx8m/clock_imx8mq.c

@@ -806,6 +806,12 @@ int clock_init(void)
 	clock_enable(CCGR_TSENSOR, 1);
 	clock_enable(CCGR_OCOTP, 1);
 
+	/* config GIC ROOT to sys_pll2_200m */
+	clock_enable(CCGR_GIC, 0);
+	clock_set_target_val(GIC_CLK_ROOT,
+			     CLK_ROOT_ON | CLK_ROOT_SOURCE_SEL(1));
+	clock_enable(CCGR_GIC, 1);
+
 	return 0;
 }
 #endif