Add Vivado version check to adi_project_create

The scripts generating the projects files typically only work correctly with
one specific version of Vivado. If a incorrect version is used the script
may fail at some point with a cryptic error message or may not fail but
create a bitstream that is not working as expected, e.g. unconnected
signals, etc. This patch adds a version check to adi_project_create that
will error out early on stating that the wrong version of Vivado was used
and which is the right version to use.

By default the required version will be the version that is required by the
common scripts. Individual projects can overwrite the required version by
setting the REQUIRED_VIVADO_VERSION variable to the required version or can
bypass the version check completely by setting the IGNORE_VERSION_CHECK
variable to 1.

Callers of the script can also disable the version check by setting the
ADI_IGNORE_VERSION_CHECK environment variable.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>