[SERIAL] sparc: Infrastructure to fix section mismatch bugs.

This patch against 2.6.23 sparc-2.6.git contains a number of minor
cleanups of the sparc serial drivers.  Initially I fixed this build
warning:

WARNING: vmlinux.o(.text+0x107a2c): Section mismatch: reference to .init.text:add_preferred_console (between 'sunserial_console_match' and 'sunserial_console_termios')

which is done by declaring sunserial_console_match() as __init.  This
resulted in build warnings on sunserial_current_minor.  To resolve
these the variable was changed so it is no longer global, and to hide
operations on it inside 2 new functions. These functions handle the
UART minor handling code that is common to all sparc serial drivers.

These changes allowed to clean up the uart counters in all the sparc
serial drivers, and the administration of minor device numbers.

Lastly, sunserial_console_termios() does not need to be exported since
it is only called from non-modular code.

Sadly, the following build warning still exists:

WARNING: vmlinux.o(__ksymtab+0x2910): Section mismatch: reference to .init.text:sunserial_console_match (between '__ksymtab_sunserial_console_match' and '__ksymtab_sunserial_unregister_minors')

This could be resolved by not exporting sunserial_console_match(), but
this is not possible at the moment because it is being called from
modular code. On the other hand, this is a bogus warning since it
comes from a ksymtab section.

Signed-off-by: Martin Habets <errandir_news@mph.eclipse.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>