dmc: add function to set up dmc from bootargs [1/1]

dmc: add function to set up dmc from bootargs [1/1]

PD#TV-8696

Problem:
DMC can't set up from bootargs. For easy debug, we need
set a monitor from bootargs.

Solution:
Add a funciton for this feature. You can using following patten
to set up a DMC monitor:

	dmc_montiro=[start_addr],[end_addr],[mask]

Example:
	setenv initargs $initargs dmc_monitor=0x0,0x20000000,0xff58
	This command set up monitor for following device on GXL:
	RANGE:0 - 20000000
	MONITOR DEVICE:
	    HDCP
	    HEVC
	    USB3.0
	    VPU READ1
	    VPU READ2
	    VPU READ3
	    VPU WRITE1
	    VPU WRITE2
	    VDEC
	    HCODEC
	    GE2DV

Verify:
P212

Change-Id: I864ff97325981fe62f18a4a4a24700b6b6ea7482
Signed-off-by: Tao Zeng <tao.zeng@amlogic.com>