meson: tighten the conditions under which expat is needed

Commit 81a0f1ec (meson: Only require libexpat when a part of the build needs it.) tried to narrow the conditions under which expat was required.

However, the condition that was added is too broad:

required: not with_platform_android or with_any_broadcom or with_any_intel

Indeed, as soon as the platform is not android, then expat will be made required, even though it was only required for Broadcom or intel drivers.

Commit 3cc390bf recently dropped the expat requirement for broadcom drivers, which leaves only intel drivers needing expat.

On non-android platforms (e.g. wayland or x11), with non-intel drivers, e.g. only freedreno (rep. by Fabio) or only virgl (rep. by Titouan), then expat is not required.

Drop the reference to android platform when deciding whether expat is required or not.

Reported-by: Fabio Estevam festevam@gmail.com
Reported-by: Titouan Christophe titouanchristophe@gmail.com
Signed-off-by: Yann E. MORIN yann.morin.1998@free.fr
Cc: Peter Seiderer ps.report@gmx.net
Cc: Eric Anholt eric@anholt.net
Cc: Kristian H. Kristensen hoegsberg@google.com