avr32: Fix misspelling of 'definitions' in comment.

Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

arch/avr32/include/asm/addrspace.h

 /*
- * Defitions for the address spaces of the AVR32 CPUs. Heavily based on
+ * Definitions for the address spaces of the AVR32 CPUs. Heavily based on
  * include/asm-sh/addrspace.h
  *
  * Copyright (C) 2004-2006 Atmel Corporation