Drop older 2017.11 SWUpdate Release

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

recipes-support/swupdate/swupdate_2017.11.bb

@@ -1,4 +0,0 @@
-require swupdate-legacy.inc
-require swupdate_tools.inc
-
-SRCREV = "c0fec16b3fc82b0db12d8ac58be7055ed1b8d439"