Drop support for SWUpdate 2020.11

Signed-off-by: Stefano Babic <sbabic@denx.de>

recipes-support/swupdate/swupdate_2020.11.bb

@@ -1,8 +0,0 @@
-require swupdate.inc
-
-SRCREV = "9763342203e32d58cbfed36550b3986b5cf0e52e"
-
-LIC_FILES_CHKSUM = "file://COPYING;md5=0636e73ff0215e8d672dc4c32c317bb3 \
-                    file://Licenses/lgpl-2.1.txt;md5=4fbd65380cdd255951079008b364516c \
-                    file://Licenses/mit.txt;md5=838c366f69b72c5df05c96dff79b35f2 \
-                    file://Licenses/Exceptions;md5=5f205fe7a7f2b056b4fa42603fe2d63a"