doc: Kconfig: Typo: square -> squared

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

drivers/i2c/Kconfig

@@ -7,7 +7,7 @@ menuconfig I2C
 	depends on HAS_IOMEM
 	select RT_MUTEXES
 	---help---
-	  I2C (pronounce: I-square-C) is a slow serial bus protocol used in
+	  I2C (pronounce: I-squared-C) is a slow serial bus protocol used in
 	  many micro controller applications and developed by Philips.  SMBus,
 	  or System Management Bus is a subset of the I2C protocol.  More
 	  information is contained in the directory <file:Documentation/i2c/>,