Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Start each of the license/copyright comments with /*-, minor shuffle of lines

Use a mutex to synchronize the driver top and bottom halves instead of
using critcal_enter() and critical_exit() to attempt to replace spl*()
calls. The critical section was calling selrecord(), which locks an
MTX_DEF mutex, which is not legal in a critical section.

Tested by: Stefan Ehmann <shoesoft@gmx.net> and "make universe"
Approved by: re (scottl)

Modify the critical section API as follows:
- The MD functions critical_enter/exit are renamed to start with a cpu_
prefix.
- MI wrapper functions critical_enter/exit maintain a per-thread nesting
count and a per-thread critical section saved state set when entering
a critical section while at nesting level 0 and restored when exiting
to nesting level 0. This moves the saved state out of spin mutexes so
that interlocking spin mutexes works properly.
- Most low-level MD code that used critical_enter/exit now use
cpu_critical_enter/exit. MI code such as device drivers and spin
mutexes use the MI wrappers. Note that since the MI wrappers store
the state in the current thread, they do not have any return values or
arguments.
- mtx_intr_enable() is replaced with a constant CRITICAL_FORK which is
assigned to curthread->td_savecrit during fork_exit().

Tested on: i386, alpha

Switch from save/disable/restore_intr() to critical_enter/exit().

Remove debugging code

Fix typo in interrupt handling code and fix bug in setting of adelay

Update to driver 2.11.
Driver now compiles on FreeBSD/Alpha, but still requires testing.
Remove a printf, submitted by Chris D. Faulhaber <jedgar@fxp.org>

Split the Bt848 driver into seperate files for
audio, tuner, card make, os dependent code and core bt848/i2c code.

Also, rewrite tuner code for FM Radio to make the code cleaner.