nv_copy_depth_to_color.c:37:10: fatal error: 'endian.h' file not found

Build error on macOS.

piglit/tests/spec/nv_copy_depth_to_color/nv_copy_depth_to_color.c:37:10: fatal error: 'endian.h' file not found
#include <endian.h>
         ^~~~~~~~~~
1 error generated.

Introduced with commit 5226c094 ("Fix compiler warnings on armv7").

commit 5226c0945b2522e06e44da1f1e06fa1a6754db6f
Author: Iskren Chernev <me@iskren.info>
Date:   Mon Jan 4 12:04:47 2021 +0200

    Fix compiler warnings on armv7
    
    When compiling on an armv7 (32bit), there are a few warnings related to
    printing 64bit numbers using printf. Switch to a portable printf token
    so both 32 and 64bit architectures can build without warnings.
    
    Also add unsigned long cast to all size_t prints.
    
    Reviewed-by: David Heidelberg <david.heidelberg@collabora.com>
    Part-of: <https://gitlab.freedesktop.org/mesa/piglit/-/merge_requests/443>

cc: @ichernev