Move MCP55_PCI_E_X_* to Kconfig. Any useless values in romstage.cs were

Move MCP55_PCI_E_X_* to Kconfig. Any useless values in romstage.cs were
not brought over to Kconfig (this applies to all #defines to 4, as
that's the default anyway)

Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@6104 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1