ARM: pxa: cm-x300: remove inline directive

cm_x300_u2d_init() function is only used through its function pointer
that is passed through platform_data structure to the driver.
Therefore it can never be inlined.
Remove the inline directive.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>