shield: adding Kconfig.shield to boostxl_ulpsense shield folder

Aligning the boostxl_ulpsense shield with all other shield
descriptions by ensuring it has a Kconfig.shield file.

This also provides the Kconfig symbol SHIELD_BOOSTXL_ULPSENSE similar
to the Kconfig symbol available for other shields.

Signed-off-by: Torsten Rasmussen <Torsten.Rasmussen@nordicsemi.no>
1 file changed