meson/configure: detect endian.h instead of trying to guess when it's available

Cc: Maxin B. John <maxin.john@gmail.com>
Cc: Khem Raj <raj.khem@gmail.com>
Cc: Rob Herring <robh@kernel.org>
Suggested-by: Jon Turney <jon.turney@dronecode.org.uk>
Signed-off-by: Eric Engestrom <eric.engestrom@imgtec.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Dylan Baker <dylan@pnwbakers.com>
Cc: <mesa-stable@lists.freedesktop.org>
(cherry picked from commit cbee1bfb)
[Juan A. Suarez: resolve trivial conflicts]
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>

Conflicts:
	meson.build

Squashed with:

configure: use AC_CHECK_HEADERS to check for endian.h

The currently we use the singular CHECK_HEADER combined with explicit
append to the DEFINES variable. That is a legacy misnomer, since it
requires us to add $DEFINES to every piece that we build.

Using the plural version of the helper sets the HAVE_ macro for us, plus
ensures it's passed to the compiler - if config.h is available in there
(not in the case of mesa) otherwise on the command line.

In hindsight, we should replace all the AC_CHECK_{FUNC,HEADER} instances
with the plural version (or even the _ONCE suffixed version) and drop
the DEFINES hacks.

Fixes: cbee1bfb ("meson/configure: detect endian.h instead of trying
to guess when it's available")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105717


Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Acked-by: Eric Engestrom <eric.engestrom@imgtec.com>
Tested-by: Clayton Craft <clayton.a.craft@intel.com>
(cherry picked from commit 5a75019a)