This commit enables ALSA dice driver to handle whole available streams.

In Dice, certain registers represent the number of available streams at
current sampling transfer frequency for both directions. The parameters
of each stream are represented in a block of register. This block is
aligned sequentially. These streams start simultaneously by writing
enable bit to a register.

This commit operates these registers when starting/stopping streams.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>