intel/genxml: don't generate identical code for different branches

Quiets 16 Coverity warnings like:

CID 1403401: Identical code for different branches (IDENTICAL_BRANCHES)

Signed-off-by: Marcin Ślusarz <marcin.slusarz@intel.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7351>
diff --git a/src/intel/genxml/gen_bits_header.py b/src/intel/genxml/gen_bits_header.py
index 16252a3..9c0f41b 100644
--- a/src/intel/genxml/gen_bits_header.py
+++ b/src/intel/genxml/gen_bits_header.py
@@ -86,19 +86,27 @@
    case 9: return ${item.get_prop(prop, 9)};
    case 8: return ${item.get_prop(prop, 8)};
    case 7:
+%if item.get_prop(prop, 7.5) == item.get_prop(prop, 7):
+      return ${item.get_prop(prop, 7)};
+%else:
       if (devinfo->is_haswell) {
          return ${item.get_prop(prop, 7.5)};
       } else {
          return ${item.get_prop(prop, 7)};
       }
+%endif
    case 6: return ${item.get_prop(prop, 6)};
    case 5: return ${item.get_prop(prop, 5)};
    case 4:
+%if item.get_prop(prop, 4.5) == item.get_prop(prop, 4):
+      return ${item.get_prop(prop, 4)};
+%else:
       if (devinfo->is_g4x) {
          return ${item.get_prop(prop, 4.5)};
       } else {
          return ${item.get_prop(prop, 4)};
       }
+%endif
    default:
       unreachable("Invalid hardware generation");
    }