pine64-pinetab: Resign from maintaining (MR 2281)

My engineering prototype 1 Gb pinetab is close to unusable,
so I can't use it to test pmOS. Also, PINE64 is no longer
selling these devices, and the ones that were sent previously
to some developers use different display panel anyway.

Martijn Braam and Dylan Van Assche agreed to maintain it.

[skip ci]

device/community/device-pine64-pinetab/APKBUILD

 # Reference: <https://postmarketos.org/devicepkg>
-# Maintainer: Alexey Min <alexey.min@gmail.com>
-# Co-Maintainer: Martijn Braam <martijn@brixit.nl>
+# Maintainer: Martijn Braam <martijn@brixit.nl>
+# Co-Maintainer: Dylan Van Assche <me@dylanvanassche.be>
 pkgname=device-pine64-pinetab
 pkgdesc="PINE64 PineTab"
 pkgver=0.10