PCI/MSI: Move cached entry functions to irq core

Required to support non PCI based MSI.

[ tglx: Extracted from Jiangs patch series ]

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --cc drivers/pci/Kconfig
Simple merge

diff --cc drivers/pci/msi.c
Simple merge

diff --cc kernel/irq/msi.c
Simple merge