Config: Exynos5800: Enable build for Peach-Pi

This adds following things :
- New config and defconfig for Peach-Pi board.
- Alterations in Kconfig and MAINTAINERS.
- Addition of CONFIG_EXYNOS5800.
- ADdition of exynos5800-peach-pi in dts list.

Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
diff --git a/board/samsung/smdk5420/Kconfig b/board/samsung/smdk5420/Kconfig
index d3a5b7f..e7aafe5 100644
--- a/board/samsung/smdk5420/Kconfig
+++ b/board/samsung/smdk5420/Kconfig
@@ -1,3 +1,19 @@
+if TARGET_PEACH_PI
+
+config SYS_BOARD
+	string
+	default "smdk5420"
+
+config SYS_VENDOR
+	string
+	default "samsung"
+
+config SYS_CONFIG_NAME
+	string
+	default "peach-pi"
+
+endif
+
 if TARGET_PEACH_PIT
 
 config SYS_BOARD