Since Linux v5.1, the pinctrl driver can use the st,package property
if provided to validate whether the ball to be configured exists
on the package. The upstream device trees provide this property,
but if we'll want barebox to supply it instead, so we can use the same
barebox binary for different SoC variants.

Signed-off-by: Ahmad Fatoum <ahmad@a3f.at>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>