lib/oe/patch.py: Dont import patches but symlink them instead

lib/oe/patch.py: Dont import patches but symlink them instead

* This patch removes the usage of quilt import <patch>
  instead it creasted a symlink to the patch in the patches
  directory and synthesizes the series file which otherwise
  would be done automatically by quilt import.

* This should help a bit in reducing build time as it avoids
  copying of the patch and also other things that quilt import
  would otherwise do.

* Tested by doing minimal-image on qemuarm.

Signed-off-by: Khem Raj <raj.khem@gmail.com>