PCI/MSI: Enable PCI_MSI_IRQ_DOMAIN support for ARC

Add ARC as an arch that supports PCI_MSI_IRQ_DOMAIN and add generation of
msi.h in the ARC arch.

Signed-off-by: Joao Pinto <jpinto@synopsys.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 67f9916..6555eb7 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -25,7 +25,7 @@
 	   If you don't know what to do here, say Y.
 
 config PCI_MSI_IRQ_DOMAIN
-	def_bool ARM || ARM64 || X86
+	def_bool ARC || ARM || ARM64 || X86
 	depends on PCI_MSI
 	select GENERIC_MSI_IRQ_DOMAIN