configure.ac: Check for the respective libdrm_* when building gallium drivers

configure.ac: Check for the respective libdrm_* when building gallium drivers

In a rare case of building gallium only, we need to
check if the required packages are available

libdrm_[intel|nouveau] - gallium[i915 i965|nouveau]

v2: r300g and r600g do not need libdrm_radeon

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Marek Olšák <maraeo@gmail.com>
(cherry picked from commit c2426bbf862850504f24e7d9765e64a75b873f3b)

Conflicts:

	configure.ac