Do not use -msynci flag for Xburst 4780 cores

synci does not provide coherency between CPU's on this device

Change-Id: I10e73fa49859e55d018884c6682b5a00b887e0a1
Signed-off-by: Chris Dearman <chris.dearman@imgtec.com>
diff --git a/core/combo/arch/mips/mips32r2-fp-xburst.mk b/core/combo/arch/mips/mips32r2-fp-xburst.mk
index 3768226..fee9cb3 100644
--- a/core/combo/arch/mips/mips32r2-fp-xburst.mk
+++ b/core/combo/arch/mips/mips32r2-fp-xburst.mk
@@ -10,7 +10,6 @@
     -mtune=mips32r2 \
     -mips32r2 \
     -mhard-float \
-    -msynci \
     -mno-fused-madd
 
 arch_variant_ldflags := \