[meta-xilinx] Thud release update

[Manjukumar Harthikote Matha]

Hi All,

Thud release branch is under-testing as of now, we will start sending patches next week and start merging to master:
Please check the tree here: 
https://github.com/Xilinx/meta-xilinx/commits/master-next

Major changes:
meta-xilinx-standalone layer to support building toolchain for MB and pmu-firmware
Proposal was sent here: 
https://lists.yoctoproject.org/pipermail/meta-xilinx/2018-September/004051.html

There are two ways to build pmu-firmware: One using multiconfig and other as two separate distros

1) multiconfig way:
	- You need to add the dependency in the image file, for example in core-image-minimal you will need
	do_image[mcdepends] = "multiconfig:zcu102:pmu:pmu-firmware:do_deploy"


	- Add conf/multiconfig in the build directory and create pmu.conf and zcu102.conf under conf/multiconfig
               pmu.conf  consists of 
	MACHINE="zynqmp-pmu"
	DISTRO="xilinx-standalone"
    	GCCVERSION="7.%"
    	TMPDIR="${TOPDIR}/pmutmp"

	zcu102.conf consists of
	MACHINE="zcu102-zynqmp"
    	DISTRO="poky"	
               - In local.conf multiconfig is enabled by: BBMULTICONFIG ?= "zcu102 pmu"
	- bitbake multiconfig:zcu102:core-image-minimal

This will build pmu-firmware in   build/pmutmp and all the linux images in build/tmp

See how to use multiconfig here:
https://www.yoctoproject.org/docs/current/mega-manual/mega-manual.html#dev-building-images-for-multiple-targets-using-multiple-configurations

2) Build each distro independently. 
Use the above pmu.conf contents in local.conf and build (bitbake pmu-firmware)
Use the above zcu102.conf contents in local.conf and build (bitbake core-image-minimal)

We are in the process of testing the Thud release branch, we are targeting Dec 12th for Thud branch.

We had a proposal to merge meta-petalinux to meta-xilinx, we will target this for next release.
meta-xilinx-tools will remain independent layer, we don't see it merging with meta-xilinx anytime soon.

Please test and provide feedback on the layer changes

Thanks,
Manju