drivers/serial/serial_ns16550.c: sparse fixes

drivers/serial/serial_ns16550.c: sparse fixes

serial_ns16550.c:222:1: warning: symbol 'eserial1_init' was not declared. Should it be static?
serial_ns16550.c:222:1: warning: symbol 'eserial1_setbrg' was not declared. Should it be static?
serial_ns16550.c:222:1: warning: symbol 'eserial1_getc' was not declared. Should it be static?
serial_ns16550.c:222:1: warning: symbol 'eserial1_tstc' was not declared. Should it be static?
serial_ns16550.c:222:1: warning: symbol 'eserial1_putc' was not declared. Should it be static?
serial_ns16550.c:222:1: warning: symbol 'eserial1_puts' was not declared. Should it be static?
serial_ns16550.c:225:1: warning: symbol 'eserial2_init' was not declared. Should it be static?
serial_ns16550.c:225:1: warning: symbol 'eserial2_setbrg' was not declared. Should it be static?
serial_ns16550.c:225:1: warning: symbol 'eserial2_getc' was not declared. Should it be static?
serial_ns16550.c:225:1: warning: symbol 'eserial2_tstc' was not declared. Should it be static?
serial_ns16550.c:225:1: warning: symbol 'eserial2_putc' was not declared. Should it be static?
serial_ns16550.c:225:1: warning: symbol 'eserial2_puts' was not declared. Should it be static?
serial_ns16550.c:228:1: warning: symbol 'eserial3_init' was not declared. Should it be static?
serial_ns16550.c:228:1: warning: symbol 'eserial3_setbrg' was not declared. Should it be static?
serial_ns16550.c:228:1: warning: symbol 'eserial3_getc' was not declared. Should it be static?
serial_ns16550.c:228:1: warning: symbol 'eserial3_tstc' was not declared. Should it be static?
serial_ns16550.c:228:1: warning: symbol 'eserial3_putc' was not declared. Should it be static?
serial_ns16550.c:228:1: warning: symbol 'eserial3_puts' was not declared. Should it be static?
serial_ns16550.c:231:1: warning: symbol 'eserial4_init' was not declared. Should it be static?
serial_ns16550.c:231:1: warning: symbol 'eserial4_setbrg' was not declared. Should it be static?
serial_ns16550.c:231:1: warning: symbol 'eserial4_getc' was not declared. Should it be static?
serial_ns16550.c:231:1: warning: symbol 'eserial4_tstc' was not declared. Should it be static?
serial_ns16550.c:231:1: warning: symbol 'eserial4_putc' was not declared. Should it be static?
serial_ns16550.c:231:1: warning: symbol 'eserial4_puts' was not declared. Should it be static?

Signed-off-by: Kim Phillips <kim.phillips@freescale.com>