Do not map $eq and $ne in cmp2lut, only proper arithmetic cmp

Signed-off-by: Clifford Wolf <clifford@clifford.at>

techlibs/common/cmp2lut.v

diff --git a/techlibs/common/cmp2lut.v b/techlibs/common/cmp2lut.v
index 0d07577..1c8192b 100644
--- a/techlibs/common/cmp2lut.v
+++ b/techlibs/common/cmp2lut.v
@@ -7,7 +7,7 @@
 // with n <= k inputs should be techmapped in this way, because this shortens the critical path
 // from n to 1 by avoiding carry chains.
 
-(* techmap_celltype = "$eq $ne $lt $le $gt $ge" *)
+(* techmap_celltype = "$lt $le $gt $ge" *)
 module _90_lut_cmp_ (A, B, Y);
 
 parameter A_SIGNED = 0;