DTS: imx53: Add imx53-kp-u-boot.dtsi file with u-boot specific property

This file adds the "u-boot,i2c-transaction-bytes" to mc34708 PMIC.

Signed-off-by: Lukasz Majewski <lukma@denx.de>
diff --git a/arch/arm/dts/imx53-kp-u-boot.dtsi b/arch/arm/dts/imx53-kp-u-boot.dtsi
new file mode 100644
index 0000000..acab9b3
--- /dev/null
+++ b/arch/arm/dts/imx53-kp-u-boot.dtsi
@@ -0,0 +1,10 @@
+/*
+ * Copyright 2019
+ * Lukasz Majewski, DENX Software Engineering, lukma@denx.de
+ *
+ * SPDX-License-Identifier:     GPL-2.0+ or X11
+ */
+
+&pmic {
+	u-boot,i2c-transaction-bytes = <3>;
+};