Bug#1035985: Built without GLESv2 support causing errors on machines only supporting GLES

[Diederik de Haas <didi.debian@cknow.org>]

Source: qt6-base
Version: 6.7.2+dfsg-5
Followup-For: Bug #1035985

I'm not sure the bug subject is accurate for my 'bug' as I'm not having
errors, but there is a real possibility the configuration is not optimal
for 'embedded' systems, namely for OpenGL ES.
It's possible EGLFS is relevant here too.

With qt5 we had packages like libqt5gui5-gles which were used on armhf
and arm64 as those systems often had OpenGL ES, but not desktop OpenGL.

Wondering how that would be wrt qt6 landed me eventually on the buildd
log where I saw the following:

```
  OpenGL:
    Desktop OpenGL ....................... yes
    OpenGL ES 2.0 ........................ no
    OpenGL ES 3.0 ........................ no
    OpenGL ES 3.1 ........................ no
    OpenGL ES 3.2 ........................ no
...
QPA backends:
  DirectFB ............................... no
  EGLFS .................................. yes
  EGLFS details:
    EGLFS OpenWFD ........................ no
    EGLFS i.Mx6 .......................... no
    EGLFS i.Mx6 Wayland .................. no
    EGLFS RCAR ........................... no
    EGLFS EGLDevice ...................... yes
    EGLFS GBM ............................ yes
    EGLFS VSP2 ........................... no
    EGLFS Mali ........................... no
    EGLFS Raspberry Pi ................... no
    EGLFS X11 ............................ yes
```

https://buildd.debian.org/status/fetch.php?pkg=qt6-base&arch=arm64&ver=6.7.2%2Bdfsg-5&stamp=1733698782&raw=0

As most/all my arm64 systems use Mali graphics (panfrost driver), it
seems beneficial if "EGLFS Mali" would be "yes" and I guess others would
like to see "yes" for their preferred platform.
And the OpenGL ES <version> all have "no" where "yes" seems preferable
for 'embedded' systems?

So hereby the request to change the configuration to better (?) support
'embedded' platforms.

Reporting this from my PineTab2 which I'd be quite willing to use for
any (pre-release) build packages.

Cheers,
  Diederik

-- System Information:
Debian Release: trixie/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'testing'), (101, 'experimental')
Architecture: arm64 (aarch64)

Kernel: Linux 6.12+unreleased-arm64-cknow (SMP w/4 CPU threads)
Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled