clk: ux500: Register msp clock lookups for u8500

Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>