kunit: software node: adhear to KUNIT formatting standard

Change CONFIG_KUNIT_DRIVER_PE_TEST to CONFIG_DRIVER_PE_KUNIT_TEST inorder
to adhear to the KUNIT *_KUNIT_TEST config name format.

Fixes: aa811e3c

 (software node: introduce CONFIG_KUNIT_DRIVER_PE_TEST)
Signed-off-by: Nico Pache <npache@redhat.com>
Link: https://lore.kernel.org/r/ef06f65f4a622cf83cce5ba2ba5a060d2aa2e1b9.1618388989.git.npache@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>