[PATCH] at91_serial -> atmel_serial: at91rm9200_usart.h

Move include/asm/arch/at91rm9200_usart.h into drivers/serial and rename
it atmel_usart.h. Also delete AVR32's version of this file.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>