x86: Rename MMCONF_BASE_ADDRESS and make it common across x86

This setting will be used by more than just ivybridge so make it common.

Also rename it to PCIE_ECAM_BASE which is a more descriptive name.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/board/google/chromebook_link/Kconfig b/board/google/chromebook_link/Kconfig
index 33a31f3..ea45472 100644
--- a/board/google/chromebook_link/Kconfig
+++ b/board/google/chromebook_link/Kconfig
@@ -22,8 +22,7 @@
 	select MARK_GRAPHICS_MEM_WRCOMB
 	select BOARD_ROMSIZE_KB_8192
 
-config MMCONF_BASE_ADDRESS
-	hex
+config PCIE_ECAM_BASE
 	default 0xf0000000
 
 config EARLY_POST_CROS_EC