firewire-lib: Add support for channel mapping
firewire-lib: rename macros, variables and functions related to CMP plug

Referring to IEC 61883-1, oMPR and iMPR, oPCR and iPCR have some fields with
the same role in the same position. This patch renames some local macros, local
variables and function arguments which has "i" in its prefix to reuse them
between oMPR and iMPR, oPCR and iPCR.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
firewire-lib: Add "direction" member to cmp_connection structure

To indicate the direction of connection, this patch adds "direction" member to
cmp_connection structure. To determine the direction, this patch also adds
"direction" argument to cmp_connection_init() function. The
cmp_connection_init() function is exported and used in snd-firewire-speakers so
this patch also affect it.

This patch just add them. Actual implementation will be done by followed
patches.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
firewire-lib: Add handling CMP output connection

To handle CMP output connection, this patch adds some macros, codes with
condition of direction and new functions. Once cmp_connection_init() is
executed with its direction, CMP input and output connection can be
handled by the same way.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
firewire-lib: introduce cmp_connection_check_used() to check others' connection
firewire-lib: Add some AV/C general commands
firewire-lib: Add quirk for BeBoB chipset
firewire-lib: Add quirks for Fireworks chipset