Rename branches with suitable spec version

[zpzigi754]

Currently, we use 3rd-project-name as submodule's branch name (e.g., 3rd-nw-linux), and most of them assume using beta0 of cca spec. I think that we should change 3rd-party branch's name to project-name-version so that it can reflect the version of spec (e.g., nw-linux-eac2). islet's branch could be also distinguished with the spec version too (e.g., main->beta0). These would facilitate maintaining our implementation according to the different spec design.

[bokdeuk-jeong]

As I remember, @bitboom suggested to use tags instead of using branches.
We need a versioning at this point before proceeding with the eac5 work.
Can we decide now what to use between tagging or taking a branch for beta0?

[zpzigi754]

For the reference, linux-cca, kvm-tool and qemu use branch while tf-rmm uses tagging like the below.

linux-cca (https://gitlab.arm.com/linux-arm/linux-cca)
[branch]
cca/rmm-v1.0-eac2
cca/rmm-v1.0-eac5
cca/rfc-v1

kvmtool-cca (https://gitlab.arm.com/linux-arm/kvmtool-cca)
[branch]
cca/rmm-v1.0-eac2
cca/rmm-v1.0-eac5
cca/rfc-v1

qemu-cca (https://jpbrucker.net/git/qemu)
[branch]
cca/rmm-v1.0-eac5
cca/rmm-v1.0-eac2
cca/rfc-v2
cca/rfc-v1

tf-rmm (https://git.trustedfirmware.org/TF-RMM/tf-rmm.git/refs/)
[tag]
rmm-spec-v1.0-eac5
rmm-spec-v1.0-eac2
tf-rmm-v0.1.0

Although I initially suggested using different branches, using either one would be totally fine.