DesignWare v3.65 hardware implements MSI controller registers in
application space.  This requires updates to the DesignWare core to
support controllers based on this older hardware.

Add msi_irq_set()/clear() interfaces to allow Set/Clear MSI IRQ enable bit
in the application register.  Also, v3.65 hardware uses the MSI_IRQ
register in application register space to raise MSI IRQ to the RC from EP.
Current code uses the standard mechanism as per PCI spec.  So add
get_msi_data() to get the address of this register so common code can
work on both v3.65 and newer hardware.

[bhelgaas: changelog]
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Pratyush Anand <pratyush.anand@st.com>
Acked-by: Mohit Kumar <mohit.kumar@st.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: Grant Likely <grant.likely@linaro.org>
CC: Rob Herring <robh+dt@kernel.org>
CC: Richard Zhu <r65037@freescale.com>
CC: Kishon Vijay Abraham I <kishon@ti.com>
CC: Marek Vasut <marex@denx.de>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Pawel Moll <pawel.moll@arm.com>
CC: Mark Rutland <mark.rutland@arm.com>
CC: Ian Campbell <ijc+devicetree@hellion.org.uk>
CC: Kumar Gala <galak@codeaurora.org>
CC: Randy Dunlap <rdunlap@infradead.org>
CC: Grant Likely <grant.likely@linaro.org>