mmc: sdhci-pci: Stop calling sdhci_enable_irq_wakeups()

sdhci_enable_irq_wakeups() is already called by sdhci_suspend_host() so
sdhci-pci should not need to call it. However sdhci_suspend_host() only
calls it if wakeups are enabled, and sdhci-pci does not enable them until
after calling sdhci_suspend_host(). So move the calls to
sdhci_pci_init_wakeup() before calling sdhci_suspend_host(), and
stop calling sdhci_enable_irq_wakeups(). That results in some
simplification because sdhci_pci_suspend_host() and
__sdhci_pci_suspend_host() no longer need to be separate functions.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>