PCI ops: MMCONF_SUPPORT_DEFAULT is required

Doing PCI config operations via MMIO window by default is a
requirement, if supported by the platform. This means chipset
or CPU code must enable MMCONF operations early in bootblock
already, or before platform-specific romstage entry.

Platforms are allowed to have NO_MMCONF_SUPPORT only in the
case it is actually not implemented in the silicon.

Change-Id: Id4d9029dec2fe195f09373320de800fcdf88c15d
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/17693
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/Kconfig

@@ -550,15 +550,6 @@ config MAX_CPUS
 	int
 	default 1
 
-config MMCONF_SUPPORT_DEFAULT
-	bool
-	default n
-
-config MMCONF_SUPPORT
-	bool
-	default y if MMCONF_SUPPORT_DEFAULT
-	default n
-
 source "src/console/Kconfig"
 
 config HAVE_ACPI_RESUME