package/sudo: cleanup the CPE_ID variables

package/sudo: cleanup the CPE_ID variables

The CPE variables are derived from the package upstream values, so they
must be set from the package values, not the other way around.

Also drop CPE_ID_VALID as it is implied as soon as at least one CPE
variable is set.

Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>