powerpc: mpc8xx: remove GEN860T, GEN806T_SC board support

These boards have been orphaned for a while and old enough.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/doc/README.scrapyard b/doc/README.scrapyard
index b984d76..4ae2a65 100644
--- a/doc/README.scrapyard
+++ b/doc/README.scrapyard
@@ -12,6 +12,7 @@
 
 Board            Arch        CPU            Commit      Removed     Last known maintainer/contact
 =================================================================================================
+gen860t          powerpc     mpc8xx         -           -           Keith Outwater <Keith_Outwater@mvis.com>
 sixnet           powerpc     mpc8xx         -           -           Dave Ellis <DGE@sixnetio.com>
 svm_sc8xx        powerpc     mpc8xx         -           -           John Zhan <zhanz@sinovee.com>
 stxxtc           powerpc     mpc8xx         -           -           Dan Malek <dan@embeddedalley.com>