PCI: consolidate the PCI_DOMAINS and PCI_DOMAINS_GENERIC config options

Move the definitions to drivers/pci and let the architectures select
them.  Two small differences to before: PCI_DOMAINS_GENERIC now selects
PCI_DOMAINS, cutting down the churn for modern architectures.  As the
only architectured arm did previously also offer PCI_DOMAINS as a user
visible choice in addition to selecting it from the relevant configs,
this is gone now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index cee1fc84..551252d 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -36,6 +36,7 @@
 	select MODULES_USE_ELF_RELA
 	select OF
 	select OF_EARLY_FLATTREE
+	select PCI_DOMAINS_GENERIC if PCI
 	select TRACING_SUPPORT
 	select VIRT_TO_BUS
 	select CPU_NO_EFFICIENT_FFS
@@ -267,12 +268,6 @@
 
 menu "Bus Options"
 
-config PCI_DOMAINS
-	def_bool PCI
-
-config PCI_DOMAINS_GENERIC
-	def_bool PCI_DOMAINS
-
 config PCI_SYSCALL
 	def_bool PCI