Fix various typos, scattered over the code.

Spelling corrections for (among other things):

* environment
* override
* variable
* ftd (should be "fdt", for flattened device tree)
* embedded
* FTDI
* emulation
* controller
diff --git a/include/configs/hikey.h b/include/configs/hikey.h
index 83d9e10..ffcc4d2 100644
--- a/include/configs/hikey.h
+++ b/include/configs/hikey.h
@@ -121,7 +121,7 @@
 				"initrd_high=0xffffffffffffffff\0" \
 				BOOTENV
 
-/* Preserve enviroment on sd card */
+/* Preserve environment on sd card */
 #define CONFIG_COMMAND_HISTORY
 
 #define CONFIG_ENV_SIZE			0x1000
diff --git a/include/configs/omap3_logic.h b/include/configs/omap3_logic.h
index 6c79643..3c11e2a 100644
--- a/include/configs/omap3_logic.h
+++ b/include/configs/omap3_logic.h
@@ -140,7 +140,7 @@
 #define CONFIG_PREBOOT \
 	"echo ======================NOTICE============================;"\
 	"echo \"The u-boot environment is not set.\";"			\
-	"echo \"If using a display a valid display varible for your panel\";" \
+	"echo \"If using a display a valid display variable for your panel\";" \
 	"echo \"needs to be set.\";"					\
 	"echo \"Valid display options are:\";"				\
 	"echo \"  2 == LQ121S1DG31     TFT SVGA    (12.1)  Sharp\";"	\
diff --git a/include/configs/pengwyn.h b/include/configs/pengwyn.h
index 1f33bc6..816c571 100644
--- a/include/configs/pengwyn.h
+++ b/include/configs/pengwyn.h
@@ -102,7 +102,7 @@
 	"run mmcboot;" \
 	"run nandboot;"
 
-/* NS16550 Configuration: primary UART via FDTI */
+/* NS16550 Configuration: primary UART via FTDI */
 #define CONFIG_SYS_NS16550_COM1		0x44e09000
 #define CONFIG_BAUDRATE			115200