Bug 11056

Test setup: https://github.com/cirosantilli/buildroot/tree/b388a47239bceb5abfe45b5ab4cdc44bdc837f7a which has very shallow patches on top of master commit 545567a8fc3eaac197c089c4ea905675d8d3dab9 which is ahead of 2018.05-rc1 then run with:

```
./run
./run-aarch64
```

Build fails for both x86 and aarch64 with:

```
>>> hello 1.0 Building
/usr/bin/make -j8 CC="/home/ciro/bak/git/buildroot/output/host/bin/aarch64-buildroot-linux-uclibc-gcc" LD="/home/ciro/bak/git/buildroot/output/host/bin/aarch64-buildroot-linux-uclibc-ld" -C /home/ciro/bak/git/bu
ildroot/output/build/hello-1.0
/home/ciro/bak/git/buildroot/output/host/bin/aarch64-buildroot-linux-uclibc-gcc -o 'hello' 'hello.c'
In file included from hello.c:2:0:
/home/ciro/bak/git/buildroot/output/host/aarch64-buildroot-linux-uclibc/sysroot/usr/include/xf86drm.h:40:17: fatal error: drm.h: No such file or directory
 #include <drm.h>
                 ^
```

for the file:

```
#include <stdio.h>
#include <xf86drm.h>
#include <xf86drmMode.h>

int main(void) {
    puts("hello");
}

```

If I remove:

```
#include <xf86drm.h>
#include <xf86drmMode.h>
```

which are provided by libdrm, then it works.

Likely something obvious to those familiar with it.

Can we add an appropriate DEPENDS or SELECTS to the Config.in?

My goal is to later run: https://github.com/dvdhrm/docs/blob/master/drm-howto/modeset.c to learn DRM. I know that there must be further settings missing since I don't have /dev/dri on aarch64, but I do on x86.