oeqa/selftest: Move base class to case module

To match the new structure of the OEQA framework.

Signed-off-by: Leonardo Sandoval <leonardo.sandoval.gonzalez@linux.intel.com>
Signed-off-by: Aníbal Limón <anibal.limon@linux.intel.com>

diff --git a/meta/lib/oeqa/selftest/base.py b/meta/lib/oeqa/selftest/case.py
similarity index 100%
rename from meta/lib/oeqa/selftest/base.py
rename to meta/lib/oeqa/selftest/case.py