microblaze: Add support for Xilinx PCI host bridge

This patch is based on powerpc patch
64f16502475ddf663169369fffff6da9b10ea9fb

We did some cleanups and removed powerpc parts.
There is one new debug early listing function too.

Exclude function is only in Debug options.

We tested in on custom board.

Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index e1fa084..c1e731b 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -267,6 +267,10 @@
 config PCI_SYSCALL
 	def_bool PCI
 
+config PCI_XILINX
+	bool "Xilinx PCI host bridge support"
+	depends on PCI
+
 source "drivers/pci/Kconfig"
 
 endmenu