Fix typo in various Kconfig file

Correct spelling typo in various Kconfig file.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/arch/mips/Kconfig.debug b/arch/mips/Kconfig.debug
index 83ed00a..5a43aa0 100644
--- a/arch/mips/Kconfig.debug
+++ b/arch/mips/Kconfig.debug
@@ -57,7 +57,7 @@
 	  options.
 
 config CMDLINE_OVERRIDE
-	bool "Built-in command line overrides firware arguments"
+	bool "Built-in command line overrides firmware arguments"
 	default n
 	depends on CMDLINE_BOOL
 	help