drivers/tty/serial/crisv10.c: remove dead #ifdef blocks

ETRAX_SERIAL_PROC_ENTRY is not defined in Kconfig.  The affected #ifdef
block has not been compiled for years, and the embedded macro, PROCSTAT,
ended up as a NOOP.  Hence, remove the block and all calls to PROCSTAT.

Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>