clock_imx8mm: grab init_uart_clk from mainline

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>

arch/arm/mach-imx/imx8m/clock_imx8mm.c

@@ -549,6 +549,43 @@ void enable_display_clk(unsigned char enable)
 	}
 }
 
+void init_uart_clk(u32 index)
+{
+	/*
+	 * set uart clock root
+	 * 24M OSC
+	 */
+	switch (index) {
+	case 0:
+		clock_enable(CCGR_UART1, 0);
+		clock_set_target_val(UART1_CLK_ROOT, CLK_ROOT_ON |
+				     CLK_ROOT_SOURCE_SEL(0));
+		clock_enable(CCGR_UART1, 1);
+		return;
+	case 1:
+		clock_enable(CCGR_UART2, 0);
+		clock_set_target_val(UART2_CLK_ROOT, CLK_ROOT_ON |
+				     CLK_ROOT_SOURCE_SEL(0));
+		clock_enable(CCGR_UART2, 1);
+		return;
+	case 2:
+		clock_enable(CCGR_UART3, 0);
+		clock_set_target_val(UART3_CLK_ROOT, CLK_ROOT_ON |
+				     CLK_ROOT_SOURCE_SEL(0));
+		clock_enable(CCGR_UART3, 1);
+		return;
+	case 3:
+		clock_enable(CCGR_UART4, 0);
+		clock_set_target_val(UART4_CLK_ROOT, CLK_ROOT_ON |
+				     CLK_ROOT_SOURCE_SEL(0));
+		clock_enable(CCGR_UART4, 1);
+		return;
+	default:
+		printf("Invalid uart index\n");
+		return;
+	}
+}
+
 int clock_init(void)
 {
 	uint32_t val_cfg0;