net: wwan: t7xx: Fix Runtime PM initialization

For PCI devices the Runtime PM refcount is incremented twice:
1. During device enumeration with a call to pm_runtime_forbid.
2. Just before a driver probe logic is called.
Because of that in order to enable Runtime PM on a given device
we have to call both pm_runtime_allow and pm_runtime_put_noidle,
once it's ready to be runtime suspended.
The former was missing causing the pm refcount to never reach 0.

Fixes: d10b3a69 ("net: wwan: t7xx: Runtime PM")
Signed-off-by: Kornel Dulęba <mindal@semihalf.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/wwan/t7xx/t7xx_pci.c

@@ -121,6 +121,8 @@ void t7xx_pci_pm_init_late(struct t7xx_pci_dev *t7xx_dev)
 	iowrite32(T7XX_L1_BIT(0), IREG_BASE(t7xx_dev) + ENABLE_ASPM_LOWPWR);
 	atomic_set(&t7xx_dev->md_pm_state, MTK_PM_RESUMED);
 
+	pm_runtime_mark_last_busy(&t7xx_dev->pdev->dev);
+	pm_runtime_allow(&t7xx_dev->pdev->dev);
 	pm_runtime_put_noidle(&t7xx_dev->pdev->dev);
 }