x86: Rename coreboot-x86 to coreboot

We only use coreboot as a target on x86 platforms, since on ARM platforms
U-Boot always runs as the primary boot loader. Rename the coreboot-x86
platform to reflect this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/board/coreboot/coreboot/MAINTAINERS b/board/coreboot/coreboot/MAINTAINERS
index 2736aa0..188906b 100644
--- a/board/coreboot/coreboot/MAINTAINERS
+++ b/board/coreboot/coreboot/MAINTAINERS
@@ -3,4 +3,4 @@
 S:	Maintained
 F:	board/coreboot/coreboot/
 F:	include/configs/chromebook_link.h
-F:	configs/coreboot-x86_defconfig
+F:	configs/coreboot_defconfig
diff --git a/configs/coreboot-x86_defconfig b/configs/coreboot_defconfig
similarity index 100%
rename from configs/coreboot-x86_defconfig
rename to configs/coreboot_defconfig
diff --git a/doc/README.x86 b/doc/README.x86
index 772e8d2..b1663a4 100644
--- a/doc/README.x86
+++ b/doc/README.x86
@@ -46,7 +46,7 @@
 Building U-Boot as a coreboot payload is just like building U-Boot for targets
 on other architectures, like below:
 
-$ make coreboot-x86_defconfig
+$ make coreboot_defconfig
 $ make all
 
 Note this default configuration will build a U-Boot payload for the QEMU board.