kernel: ksysfs: initialize kernel_kobj earlier

kernel: ksysfs: initialize kernel_kobj earlier

Software nodes depend on kernel_kobj which is initialized pretty late
into the boot process - as a core_initcall(). Ahead of moving the
software node initialization to driver_init() we must first make
kernel_kobj available before it.

Make ksysfs_init() visible in a new header - ksysfs.h - and call it in
do_basic_setup() right before driver_init().

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260402-nokia770-gpio-swnodes-v5-1-d730db3dd299@oss.qualcomm.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>