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>

configure.ac

@@ -865,6 +865,7 @@ fi
 AC_HEADER_MAJOR
 AC_CHECK_HEADER([xlocale.h], [DEFINES="$DEFINES -DHAVE_XLOCALE_H"])
 AC_CHECK_HEADER([sys/sysctl.h], [DEFINES="$DEFINES -DHAVE_SYS_SYSCTL_H"])
+AC_CHECK_HEADER([endian.h], [DEFINES="$DEFINES -DHAVE_ENDIAN_H"])
 AC_CHECK_FUNC([strtof], [DEFINES="$DEFINES -DHAVE_STRTOF"])
 AC_CHECK_FUNC([mkostemp], [DEFINES="$DEFINES -DHAVE_MKOSTEMP"])
 AC_CHECK_FUNC([timespec_get], [DEFINES="$DEFINES -DHAVE_TIMESPEC_GET"])