Toolchain: Remove obsolete special script for uClibc

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Build: Update toolchain script to produce distributable toolchain

Build toolchain that is ready to be distributed by adding rel-rpath to the
options and making a static build. Also add a better support for the HS.
Additionally update log handling to make it shorter in code, also change
location where build logs are stored to the separate directory for each
toolchain ($toolchain/build/<logs>).

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Common: Minor comment added

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Common: Add function to get Git revision

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Rootfs: Add script that build rootfs

Also add a basic defconfigs for HS and 700.

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Linux: Add script to build vmlinux

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>