ASoC: simple-card-utils: remove strict limitation of bit/frame master

Current asoc_simple_card_parse_daifmt is keeping backward compatibility
for bitmaster/framemaster which didn't use phandle.
The keep compatibility, it is checking prefix length, but it is
too strict. let's loosen it. Otherwise, OF-graph base sound card
which doesn't have prefix can't detect daifmt.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>