package/openjdk{, -bin}: bump latest to version 16.0.1+9

package/openjdk{, -bin}: bump latest to version 16.0.1+9

When introducing OpenJDK to buildroot, the OpenJDK project did not put
releases on their GitHub page. Since then, the OpenJDK developers have
not only added OpenJDK releases to Github, they are starting to phase
out adding releases to their public-facing mercurial repository.

Compare the following URLs:
https://wiki.openjdk.java.net/display/JDKUpdates/JDK+14u
https://wiki.openjdk.java.net/display/JDKUpdates/JDK+15u
https://wiki.openjdk.java.net/display/JDKUpdates/JDK+16u

With JDK14, only the mercurial repository is listed. With OpenJDK15,
both the GitHub and mercurial repository are listed. Finally, with
OpenJDK16, only the GitHub repository is listed.

For consistency's sake, and for the version bump of JDK latest from 14
to 16 do the following:

  - Change the repository for OpenJDK14 to point to the official GitHub
    repository,

  - In order to simplify and reuse the GitHub URL, modify the
    OPENJDK_VERSION_MAJOR and OPENJDK_VERSION_MINOR definitions to only
    include a single number for the MAJOR definition.

  - Change openjdk-bin.mk to also use the same format as the openjdk.mk
    file

Unfortunately, we can't yet do the switch for OpenJDK11: the Github
repository is missing a Mercurial-related file, so that the archive
for OpenJDK11 11.0.11+9 would change from the one we already have on
s.b.o and that people would alreay have locally, and we'd have a hash
mismatch, either on master, or on all pur previous relases. OpenJDK11
just got a new release mere hours ago (as of this writing), but it
hasn't yet trickled down to AdoptOpenJDK/openjdk11-binaries, so we
can't do the bump just yet...

Add a note to the OpenJDK11 case, to prepare the migration to Github
with the next version bump.

Finally, remove upstreamed patch 0001-fix-gcc-10-support.patch as it's
no longer needed.

Signed-off-by: Adam Duskett <aduskett@gmail.com>
[yann.morin.1998@free.fr:
  - meld the github switch and 14->16 bump together
  - drop the github switch for 11 9because hash mismatch)
  - expand commit log accordingly
]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>