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/doc/README.marubun-pcmcia b/doc/README.marubun-pcmcia
index d3563a3..0a363b2 100644
--- a/doc/README.marubun-pcmcia
+++ b/doc/README.marubun-pcmcia
@@ -34,7 +34,7 @@
 	ex.	#define CONFIG_PCMCIA_SLOT_A    1
 
     * CONFIG_SYS_MARUBUN_MRSHPC
-	This is MR-SHPC-01 PCMCIA controler base address.
+	This is MR-SHPC-01 PCMCIA controller base address.
 	You should do the setting matched to your environment.
 	ex.  #define CONFIG_SYS_MARUBUN_MRSHPC 0xb03fffe0
 	     ( for MS7722SE01 environment )