package/openjdk: restrict to support architectures

package/openjdk: restrict to support architectures

This list is taken from make/autoconf/platform.m4 and fixes
http://autobuild.buildroot.net/results/df7/df7f393ec62f0e38034837ffa591ac5af424c373
http://autobuild.buildroot.net/results/c57/c5782d6b52516d07469adf6600d4fc69c4016157
http://autobuild.buildroot.net/results/f36/f36b96c91604dda021ee05dd0a79c4f7e89e5a5b

Signed-off-by: Adam Duskett <Aduskett@gmail.com>
[Thomas:
 - rename option to BR2_PACKAGE_OPENJDK_ARCH_SUPPORTS
 - actually use it in the Config.in comments]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>