nvidia: build the nvidia-uvm kernel module required by CUDA.

Also re-add the 3.18 patch, this seems to be still necessary.

Close #935

srcpkgs/nvidia/files/linux-3.18.patch

@@ -0,0 +1,13 @@
+--- kernel/nv-drm.c    2014-11-08 00:57:53.000000000 +0100
++++ kernel/nv-drm.c    2014-11-13 21:03:37.589650873 +0100
+@@ -128,6 +128,10 @@ static struct drm_driver nv_drm_driver =
+     .gem_prime_vmap = nv_gem_prime_vmap,
+     .gem_prime_vunmap = nv_gem_prime_vunmap,
+ 
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 18, 0)
++    .set_busid = drm_pci_set_busid,
++#endif
++
+     .name = "nvidia-drm",
+     .desc = "NVIDIA DRM driver",
+     .date = "20130102",

srcpkgs/nvidia/template

@@ -4,7 +4,7 @@ _desc="NVIDIA drivers for linux"
 
 pkgname=nvidia
 version=346.35
-revision=1
+revision=2
 maintainer="Juan RP <xtraeme@gmail.com>"
 license="Propietary NVIDIA license"
 homepage="http://www.nvidia.com"
@@ -35,6 +35,10 @@ do_extract() {
 	./${_pkg}.run --extract-only
 	rm -f ${_pkg}.run
 }
+do_configure() {
+	cd ${_pkg}
+	patch -sNp0 -i ${FILESDIR}/linux-3.18.patch
+}
 do_install() {
 	cd ${_pkg}
 
@@ -140,12 +144,16 @@ do_install() {
 
 	# dkms pkg
 	vmkdir usr/src/nvidia-${version}
+	# add nvidia-uvm dkms submodule too.
+	cat kernel/uvm/dkms.conf.fragment >> kernel/dkms.conf
 	vcopy "kernel/*" usr/src/nvidia-${version}
 
 	# systemd modules-load.d(5) file.
 	vmkdir usr/lib/modules-load.d
 	echo "nvidia" > ${DESTDIR}/usr/lib/modules-load.d/nvidia.conf
+	echo "nvidia-uvm" > ${DESTDIR}/usr/lib/modules-load.d/nvidia-uvm.conf
 	chmod 644 ${DESTDIR}/usr/lib/modules-load.d/nvidia.conf
+	chmod 644 ${DESTDIR}/usr/lib/modules-load.d/nvidia-uvm.conf
 
 	# Blacklist nouveau.
 	vmkdir usr/lib/modprobe.d