make mp lib compile for power arch.

Reference: /n/atom/patch/applied2013/apemppower
Date: Thu Dec 19 23:20:37 CET 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/ape/lib/mp/power/mkfile	Thu Dec 19 23:20:28 2013
+++ /sys/src/ape/lib/mp/power/mkfile	Thu Dec 19 23:20:28 2013
@@ -8,7 +8,6 @@
 	mpvecdigmuladd.s\
 	mpvecdigmulsub.s\
 	mpvecsub.s\
-	mpdigdiv.s\
 
 HFILES=\
 	/sys/include/ape/mp.h\