ata: sata_dwc_460ex: enable SATA interrupts only after IRQ handler is registered

In the Linux kernel, the following vulnerability has been resolved: ata: sata_dwc_460ex: enable SATA interrupts only after IRQ handler is registered sata_dwc_enable_interrupts() is called before platform_get_irq() and ata_host_activate(), leaving the SATA controller's interrupt mask enabled without a registered handler. If a later step fails (irq request, phy init, etc.) or if the controller asserts an interrupt during probe, the irq line may fire with no handler, causing a spurious interrupt storm. Move sata_dwc_enable_interrupts() after ata_host_activate() so that interrupts are only unmasked once the handler is registered and the core is fully initialized.