MIPS: dts: Change upper case to lower case

All the upper case in unit-address and hex constants are
changed to lower case according to the DT conventions.

Signed-off-by: Songjun Wu <songjun.wu@linux.intel.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Patchwork: https://patchwork.linux-mips.org/patch/20768/
Cc: yixin.zhu@linux.intel.com
Cc: chuanhua.lei@linux.intel.com
Cc: hauke.mehrtens@intel.com
Cc: devicetree@vger.kernel.org
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>