anv: add the X related and Wayland CFLAGS to VULKAN_ENTRYPOINT_CPPFLAGS
anv: add the X related and Wayland CFLAGS to VULKAN_ENTRYPOINT_CPPFLAGS

Otherwise we will fail to find the headers in some scenarios.

Cc: <59f39c0db42d4479a46b02d4d2bc11120e37bb44@lists.freedesktop.org>
Signed-off-by: Emil Velikov <f20878473f414da183da19ee25c8722cc1d711e4@collabora.com>
Reported-by: Tobias Klausmann <694fb395a4e886b29a8a86dfcf2bcf3dfc9710a7@mni.thm.de>
Tested-by: Tobias Klausmann <694fb395a4e886b29a8a86dfcf2bcf3dfc9710a7@mni.thm.de>
Reviewed-by: Tobias Klausmann <694fb395a4e886b29a8a86dfcf2bcf3dfc9710a7@mni.thm.de>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler