Fix spelling in documentation and comments (similiar -> similar)

This bug was detected by codespell.
In mips_mipssim.c a grammatical error was fixed, too.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

docs/libcacard.txt

@@ -399,7 +399,7 @@ functions:
       This function will automatically generate the appropriate new reader
       events and add the reader to the list.
 
-  To create a new card, the virtual card emulator will call a similiar
+  To create a new card, the virtual card emulator will call a similar
   function.
 
            VCard *vcard_new(VCardEmul *card_emul,

hw/mips_mipssim.c

 /*
  * QEMU/mipssim emulation
  *
- * Emulates a very simple machine model similiar to the one use by the
+ * Emulates a very simple machine model similar to the one used by the
  * proprietary MIPS emulator.
  * 
  * Copyright (c) 2007 Thiemo Seufer

qemu-doc.texi

@@ -1749,7 +1749,7 @@ PC Keyboard
 IDE controller
 @end itemize
 
-The mipssim pseudo board emulation provides an environment similiar
+The mipssim pseudo board emulation provides an environment similar
 to what the proprietary MIPS emulator uses for running Linux.
 It supports:
 
@@ -2141,7 +2141,7 @@ Xtensa emulator pseudo board "sim"
 Avnet LX60/LX110/LX200 board
 @end itemize
 
-The sim pseudo board emulation provides an environment similiar
+The sim pseudo board emulation provides an environment similar
 to one provided by the proprietary Tensilica ISS.
 It supports: