ARM: ux500: Remove duplicated assignment of ab8500_platdata

Since: "05ec260e mfd: db8500-prcmu: update resource passing", the AB8500's
platform data 'ab8500_platdata' is passed directly as an attribute to
'db8500_prcmu_pdata', so there's no requirement to assign it a second
time. In fact, it's only due to an ordering issue that the entire
'db8500_prcmu_pdata' data structure isn't completely over-written by the
assignment in u8500_init_devices().

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