kernel.bbclass: Allow modules*.tar.gz generation to be inhibited
The modules.tar.gz archive is sometimes of no value and it can take
a noticeable time to build if many modules were enabled in the kernel
configuration. The extraneous file also contributes to deploy/ clutter
and is a waste of disk space.
Allow it to be suppressed by setting MODULE_TARBALL_DEPLOY="0".
Signed-off-by: Phil Blundell <pb@pbcl.net> Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com> Signed-off-by: Saul Wold <sgw@linux.intel.com>
