X11R7 issue

Hi,
i try to compile xfce4 with pkgsrc-2016Q1 with NetBSD 7.0, no problem 
for xfce4.
I doing a list of ports i must compile for xf86 or X11R7, this the list :
--------------------------------------------------------------------------------------------------
x11/modular-xorg-server/ (1)
meta-pkgs/modular-xorg-drivers/ (2)
meta-pkgs/modular-xorg-fonts/ (3)
meta-pkgs/modular-xorg-apps/
x11/modular-xorg-server/
meta-pkgs/modular-xorg-fonts/
x11/xf86-input-keyboard/
x11/xf86-input-mouse/
x11/xf86-video-vmware/
x11/xauth/
x11/xinit/

I cannot to compile the number 2 : meta-pkgs/modular-xorg-drivers
i've got issue this my output :
**********************************************************************
checking for LIBDRM_AMDGPU... no
configure: error: Package requirements (libdrm_amdgpu) were not met:

No package 'libdrm_amdgpu' found

Consider adjusting the PKG_CONFIG_PATH environment variable if you
installed software in a non-standard prefix.

Alternatively, you may set the environment variables LIBDRM_AMDGPU_CFLAGS
and LIBDRM_AMDGPU_LIBS to avoid the need to call pkg-config.
See the pkg-config man page for more details.
*** Error code 1

Stop.
make[2]: stopped in /usr/pkgsrc/x11/xf86-video-amdgpu
*** Error code 1

Stop.
make[1]: stopped in /usr/pkgsrc/x11/xf86-video-amdgpu
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc/meta-pkgs/modular-xorg-drivers
udct-lune#

*********************************************************************

I see the variable
LIBDRM_AMDGPU_CFLAGS
and LIBDRM_AMDGPU_LIBS ,

i thing that a declare it for wich value into the mk.conf ?


Regards
philo