ARM: dts: keystone-k2hk-evm: Add U-boot specific dtsi file

With Davinci I2C switching to device model, K2HK requires U-boot specific
device tree entries. This is only required for I2C 1 which is needed
extremely early during the boot process.

Fixes: 1743d040 ("ARM: keystone: Enable DM_I2C by default")
Reported-by: Yan Liu <yan-liu@ti.com>
Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>