bus: imx-weim: remove incorrect __init annotations

The probe function is no longer __init, so anything it calls now
must also be available at runtime, as Kbuild points out when building
with clang-9:

WARNING: vmlinux.o(.text+0x6e7040): Section mismatch in reference from the function weim_probe() to the function .init.text:imx_weim_gpr_setup()
The function weim_probe() references
the function __init imx_weim_gpr_setup().
This is often because weim_probe lacks a __init
annotation or the annotation of imx_weim_gpr_setup is wrong.

WARNING: vmlinux.o(.text+0x6e70f0): Section mismatch in reference from the function weim_probe() to the function .init.text:weim_timing_setup()
The function weim_probe() references
the function __init weim_timing_setup().
This is often because weim_probe lacks a __init
annotation or the annotation of weim_timing_setup is wrong.

Remove the remaining __init markings that are now wrong.

Fixes: 4a92f078 ("bus: imx-weim: use module_platform_driver()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>