ARM: dts: SiRF: add lost usp1_uart_nostreamctrl pin group for atlas6

this patch adds lost usp1_uart_nostreamctrl pin group for atlas6, which
matches with the change in drivers/pinctrl/sirf/pinctrl-atlas6.c.

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>