rtc: asm9260: remove incorrect __init/__exit annotations

The probe and remove callbacks of the platform driver are marked __init
and __exit, respectively. However, this is not a correct way to annotate
them, as it will result in those sections to be discarded at link time
or after boot, while we can actually call them again based on manual
unbinding, or deferred probing.

Kbuild warns about the problem:

WARNING: drivers/rtc/rtc-asm9260.o(.data+0x0): Section mismatch in reference from the variable asm9260_rtc_driver to the function .init.text:asm9260_rtc_probe()

This removes the annotations, so we no longer branch into missing
code and avoid the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 125e550f

 ("rtc: add Alphascale asm9260 driver")
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>