[ARM] 4905/1: [AT91] Atmel SAM9 boards updated to new-style UART initialization

Convert the Atmel SAM9260-EK, SAM9261-EK, SAM9263-EK and SAM9RL-EK
boards to use the new-style UART initialization.

Signed-off-by: Sedji Gaouaou <sedji.gaouaou@atmel.com>
Signed-off-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>