intel: fix build error

  CCLD   test_decode
./.libs/libdrm_intel.so: undefined reference to `drmPrimeHandleToFD'
./.libs/libdrm_intel.so: undefined reference to `drmPrimeFDToHandle'
collect2: ld returned 1 exit status

From Adam Jackson's explaination:

  most distros have changed it so ld defaults to --no-copy-dt-needed-entries,
  so if you use something from libdrm you can't just assume libdrm_intel
  will bring it in for you, you have to be explicit

Signed-off-by: Rob Clark <rob@ti.com>