pcie: msi: pci_msi_enable() to take IRQ as parameter

This changes pci_msi_enable() to take IRQ number as a function
parameter. The old behavior relies on putting the IRQ number
into the interrupt line register in the PCI config space
during IRQ allocation, and reading it back when enabling IRQ.
However, the interrupt line register is only required to be
read-/writable when legacy interrupt is supported on the device.
Otherwise it has undefined behavior. On ACRN, they don't even
care about this register and always wires it to 0x00.
So this commit changes the behavior in pci_msi_enable() to not
require reading back the interrupt line register and instead
takes the IRQ number via function parameter.

Fixes #36765

Signed-off-by: Daniel Leung <daniel.leung@intel.com>