[AMDGPU] Remove magic constants from V_PK_ADD_F32 pattern. NFC (llvm#164335)

Author: rampitec

llvm/lib/Target/AMDGPU/SIInstructions.td

@@ -2223,8 +2223,8 @@ def : GCNPat <
 
 def : GCNPat <
   (DivergentUnaryFrag<fneg> (v2f32 VReg_64:$src)),
-  (V_PK_ADD_F32 11 /* OP_SEL_1 | NEG_LO | HEG_HI */, VReg_64:$src,
-                11 /* OP_SEL_1 | NEG_LO | HEG_HI */, (i64 0),
+  (V_PK_ADD_F32 !or(SRCMODS.OP_SEL_1, SRCMODS.NEG, SRCMODS.NEG_HI), VReg_64:$src,
+                !or(SRCMODS.OP_SEL_1, SRCMODS.NEG, SRCMODS.NEG_HI), (i64 0),
                 0, 0, 0, 0, 0)
 > {
   let SubtargetPredicate = HasPackedFP32Ops;