RFR: 8243590: Bump boot jdk to JDK 14 on aarch64 at Oracle

[Mikael Vidstedt]

The (minimum) boot JDK was recently bumped to JDK 14, and that needs to be reflected in the configuration for linux-aarch64 builds at Oracle as well:

JBS: https://bugs.openjdk.java.net/browse/JDK-8243590 <https://bugs.openjdk.java.net/browse/JDK-8243590>
Webrev: http://cr.openjdk.java.net/~mikael/webrevs/8243590/webrev.00/open/webrev/ <http://cr.openjdk.java.net/~mikael/webrevs/8243590/webrev.00/open/webrev/>

Cheers,
Mikael