device-kobo-clara: remove mesa-dri-gallium dep (MR 3371)

Having mesa-dri-gallium installed causes Xorg to crash. See #1658.
Furthermore, display works without at least with near-mainline kernel,
tested with osk-sdl and xfce4.
So if specific applications depend on it, it should be added as a
dependency there.

This reverts MR 3306

This is just a hotfix, Xorg/mesa should be tamed to not crash here
but analyzing that costs time.

device/testing/device-kobo-clara/APKBUILD

 # Reference: <https://postmarketos.org/devicepkg>
 pkgname=device-kobo-clara
 pkgdesc="Kobo Clara HD"
-pkgver=0.5
+pkgver=0.6
 pkgrel=0
 url="https://postmarketos.org"
 license="MIT"
@@ -9,7 +9,6 @@ arch="armv7"
 options="!check !archcheck"
 depends="
 	kobo-epdc-extractor
-	mesa-dri-gallium
 	perl
 	postmarketos-base
 	u-boot-kobo-clara