i2c: imx_lpi2c: add ipg clk

The controller needs two clk, per clk and ipg clk,
so let's add ipg clk.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/drivers/i2c/imx_lpi2c.c b/drivers/i2c/imx_lpi2c.c
index 4586d43..2de99d0 100644
--- a/drivers/i2c/imx_lpi2c.c
+++ b/drivers/i2c/imx_lpi2c.c
@@ -471,6 +471,17 @@
 			dev_err(bus, "Failed to enable per clk\n");
 			return ret;
 		}
+
+		ret = clk_get_by_name(bus, "ipg", &i2c_bus->ipg_clk);
+		if (ret) {
+			dev_err(bus, "Failed to get ipg clk\n");
+			return ret;
+		}
+		ret = clk_enable(&i2c_bus->ipg_clk);
+		if (ret) {
+			dev_err(bus, "Failed to enable ipg clk\n");
+			return ret;
+		}
 	} else {
 		/* To i.MX7ULP, only i2c4-7 can be handled by A7 core */
 		ret = enable_i2c_clk(1, bus->seq);