gallium: extend resource_resolve to accommodate BlitFramebuffer

gallium: extend resource_resolve to accommodate BlitFramebuffer

Resolve via glBlitFramebuffer allows resolving a sub-region of a
renderbuffer to a different location in any mipmap level of some
other texture, and, with a new extension, even scaling. Therefore,
location and size parameters are needed.

The mask parameter was added because resolving only depth or only
stencil of a combined buffer is possible as well.

Full information about the blit operation allows the drivers to
take the most efficient path they possibly can.