codecparsers: h264: fix derivation of default scaling lists.

When useDefaultScalingMatrixFlag is computed to be 1 while parsing
scaling_list(), then the scaling list shall be inferred to be equal
to the default list (7.4.2.1.1.1). That default list is really one
of Default_4x4_{Intra,Inter} or Default_8x8_{Intra,Inter} and not
one from fall-back rule sets A or B.

This fixes parsing for FRExt1_Panasonic_D, FRExt2_Panasonic_C,
FRExt3_Panasonic_E and FRExt4_Panasonic_B.

https://bugzilla.gnome.org/show_bug.cgi?id=724518

Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
Signed-off-by: Zhong Cong <congx.zhong@intel.com>