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>

scons/gallium.py

@@ -354,6 +354,9 @@ def generate(env):
         if check_header(env, 'xlocale.h'):
             cppdefines += ['HAVE_XLOCALE_H']
 
+        if check_header(env, 'endian.h'):
+            cppdefines += ['HAVE_ENDIAN_H']
+
         if check_functions(env, ['strtod_l', 'strtof_l']):
             cppdefines += ['HAVE_STRTOD_L']