autoconf/scons: bump libdrm to 2.4.75

We'll be using the drmGetDevice[s]2 API in src/loader with next patch.

v2: Rebase.

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com> (v1)
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com> (v1)
Tested-by: Mike Lothian <mike@fireburn.co.uk>
diff --git a/configure.ac b/configure.ac
index 1d81fcc..6b65ff8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -72,7 +72,7 @@
 # codifies which drivers need which version of libdrm. Any libdrm
 # version dependencies in non-driver-specific code should be reflected
 # in the first entry.
-LIBDRM_REQUIRED=2.4.66
+LIBDRM_REQUIRED=2.4.75
 LIBDRM_RADEON_REQUIRED=2.4.71
 LIBDRM_AMDGPU_REQUIRED=2.4.63
 LIBDRM_INTEL_REQUIRED=2.4.75
diff --git a/scons/gallium.py b/scons/gallium.py
index 665d66a..a411277 100755
--- a/scons/gallium.py
+++ b/scons/gallium.py
@@ -648,7 +648,7 @@
     env.PkgCheckModules('X11', ['x11', 'xext', 'xdamage >= 1.1', 'xfixes', 'glproto >= 1.4.13', 'dri2proto >= 2.8'])
     env.PkgCheckModules('XCB', ['x11-xcb', 'xcb-glx >= 1.8.1', 'xcb-dri2 >= 1.8'])
     env.PkgCheckModules('XF86VIDMODE', ['xxf86vm'])
-    env.PkgCheckModules('DRM', ['libdrm >= 2.4.66'])
+    env.PkgCheckModules('DRM', ['libdrm >= 2.4.75'])
 
     if env['x11']:
         env.Append(CPPPATH = env['X11_CPPPATH'])