Adds a CONFIG_MAX_PCI_BUSES to pci_locate_device()

Default is 255.

This allows mainboard configs for working across various groups
of boards that differ a device that may not loaded.

If you search for a device that is not loaded and max buses is 255
then there can be up to a 8 second delay to search the entire PCI space.
Board configs that know thier max bus can limit this search space.


git-svn-id: svn://svn.coreboot.org/coreboot/trunk@2273 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

src/config/Options.lb

@@ -490,6 +490,11 @@ define CONFIG_SYS_CLK_FREQ
 	export used
 	comment "System clock frequency in MHz"
 end
+define CONFIG_MAX_PCI_BUSES
+	default 255
+	export always
+	comment "Maximum number of PCI buses to search for devices"
+end
 ###############################################
 # SMP options
 ###############################################