powerpc: mpc8xx: remove stxxtc board support

This board has 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 6f28ab0..b7b16d1 100644
--- a/doc/README.scrapyard
+++ b/doc/README.scrapyard
@@ -12,6 +12,7 @@
 
 Board            Arch        CPU            Commit      Removed     Last known maintainer/contact
 =================================================================================================
+stxxtc           powerpc     mpc8xx         -           -           Dan Malek <dan@embeddedalley.com>
 omap5912osk      arm         arm926ejs      -           -           Rishi Bhattacharya <rishi@ti.com>
 p1023rds         powerpc     mpc85xx        d0bc5140    2014-07-22  Roy Zang <tie-fei.zang@freescale.com>
 spc1920          powerpc     mpc8xx         98ad54be    2014-07-07