ARM: ux500: Fix SSP register address format

SSP won't probe unless the specified register address format
is correct i.e. we have to specify that the address is in hex.
After this patch has been applied, the SSP (SPI) driver probes
as expected.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>