package/{mesa3d, mesa3d-headers}: bump version to 18.2.0

package/{mesa3d, mesa3d-headers}: bump version to 18.2.0

Upstream unconditionally enabled floating-point textures:
https://cgit.freedesktop.org/mesa/mesa/commit/?h=18.2&id=66673bef941af344314fe9c91cad8cd330b245eb

x11 support depends on xlib_libXrandr now:
https://cgit.freedesktop.org/mesa/mesa/commit/configure.ac?h=18.2&id=3f960c1338713d317ce6463be68cee162c968d8d

Removed 0003-musl-time-h.patch, patch was applied upstream.

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>