[PARISC] fix section mismatch in superio serial drivers

This patch fixes two section mismatches in superio serial setup:
WARNING: drivers/built-in.o(.text.superio_serial_init+0x78): Section mismatch: reference to .init.text:early_serial_setup (after 'superio_serial_init')
WARNING: drivers/built-in.o(.text.superio_serial_init+0xa4): Section mismatch: reference to .init.text:early_serial_setup (after 'superio_serial_init')

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>