drivers/net/irda: fix sparse warnings: make symbols static

Fix this sparse warnings:

  drivers/net/irda/ma600-sir.c:239:5: warning: symbol 'ma600_reset' was not declared. Should it be static?
  drivers/net/irda/smsc-ircc2.c:875:5: warning: symbol 'smsc_ircc_hard_xmit_sir' was not declared. Should it be static?
  drivers/net/irda/smsc-ircc2.c:1131:6: warning: symbol 'smsc_ircc_set_sir_speed' was not declared. Should it be static?
  drivers/net/irda/smsc-ircc2.c:1897:6: warning: symbol 'smsc_ircc_sir_start' was not declared. Should it be static?
  drivers/net/irda/w83977af_ir.c:150:5: warning: symbol 'w83977af_open' was not declared. Should it be static?
  drivers/net/irda/w83977af_ir.c:313:5: warning: symbol 'w83977af_probe' was not declared. Should it be static?
  drivers/net/irda/w83977af_ir.c:412:6: warning: symbol 'w83977af_change_speed' was not declared. Should it be static?
  drivers/net/irda/w83977af_ir.c:492:5: warning: symbol 'w83977af_hard_xmit' was not declared. Should it be static?
  drivers/net/irda/w83977af_ir.c:734:5: warning: symbol 'w83977af_dma_receive' was not declared. Should it be static?
  drivers/net/irda/w83977af_ir.c:806:5: warning: symbol 'w83977af_dma_receive_complete' was not declared. Should it be static?

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: David S. Miller <davem@davemloft.net>