tegra: Replace 'Norrin' with 'Nyan-big' and fix typo

With the rename the MAINTAINER file was not updated. Fix it and the
'Chrombook' typo in Kconfig.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>

arch/arm/mach-tegra/tegra124/Kconfig

@@ -10,7 +10,7 @@ config TARGET_JETSON_TK1
 	select CPU_V7_HAS_VIRT if !SPL_BUILD
 
 config TARGET_NYAN_BIG
-	bool "Google/NVIDIA Nyan-big Chrombook"
+	bool "Google/NVIDIA Nyan-big Chromebook"
 	help
 	  Nyan Big is a Tegra124 clamshell board that is very similar
 	  to venice2, but it has a different panel, the sdcard CD and WP

board/nvidia/nyan-big/MAINTAINERS

@@ -1,4 +1,4 @@
-NORRIN BOARD
+NYAN-BIG BOARD
 M:	Allen Martin <amartin@nvidia.com>
 S:	Maintained
 F:	board/nvidia/nyan-big/