omap: rx51: Switch rx51_tpa6130a2_data __initdata to__initdata_or_module

If the TPA6130 is compiled as module the id and power_gpio values are
arbitrary at module probing time since the rx51_tpa6130a2_data was marked as
__initdata. Fix this by using __initdata_or_module. Then __initdata is
defined only if the kernel is built without CONFIG_MODULES and omitted
otherwise.

Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>