MIPS: Netlogic: Built-in DTB for XLP2xx SoC boards

Add a default built-in device tree for XLP2xx SoC. The new file
xlp_fvp.dts has updated entries for I2C and memory.

Signed-off-by: Ganesan Ramalingam <ganesanr@broadcom.com>
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5705/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>