drivers/char/hvc_console.c: cleanups

- make needlessly global code static
- remove the unused EXPORT_SYMBOL's

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>