ARM: dts: keystone: Add i2c device nodes

Keystone2 based SOCs supports 3 instances of i2c controllers. Add
the device nodes for them. The i2c0 child device AT24C1024 EEPROM node
is also added. When different board variants are added in future, it
can be moved to the supported boards from common SOC file.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>