ata: ahci_brcmstb: Fix warnings with CONFIG_PM_SLEEP=n
When CONFIG_PM_SLEEP is disabled, brcm_ahci_{suspend,resume} are not
used, which causes such a build warning to occur:
CC drivers/ata/ahci_brcmstb.o
drivers/ata/ahci_brcmstb.c:212:12: warning: 'brcm_ahci_suspend' defined
but not used [-Wunused-function]
static int brcm_ahci_suspend(struct device *dev)
^
drivers/ata/ahci_brcmstb.c:224:12: warning: 'brcm_ahci_resume' defined
but not used [-Wunused-function]
static int brcm_ahci_resume(struct device *dev)
^
LD drivers/ata/built-in.o