target-ppc: Add DFP to Emulated Instructions Flag

Decimal Floating Point is emulated, so add it the mask.  This will
fix the erroneous message:

  Warning: Disabling some instructions which are not emulated by TCG (0x0, 0x4)
Signed-off-by: NTom Musta <tommusta@gmail.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

target-ppc/cpu.h

@@ -2012,7 +2012,7 @@ enum {
                         PPC2_DIVE_ISA206 | PPC2_ATOMIC_ISA206 | \
                         PPC2_FP_CVT_ISA206 | PPC2_FP_TST_ISA206 | \
                         PPC2_BCTAR_ISA207 | PPC2_LSQ_ISA207 | \
-                        PPC2_ALTIVEC_207 | PPC2_ISA207S)
+                        PPC2_ALTIVEC_207 | PPC2_ISA207S | PPC2_DFP)
 };
 
 /*****************************************************************************/