This adds new entry under Settings -> Services (where all Lakka related
services are currently available, such as switches for services like
SSH, Samba, etc.). By adding this the users do not have to use the
command line / access the file system directly to change their local
time zone to adjust the date/time displayed in RetroArch.
These change handler functions had incorrect parameter (void *) instead
of (rarch_setting_t *) and were also spawning new local pointer to the
settings and other local variables, which was not necessary, as one can
use the value from the call (setting->target.value.boolean in these
cases).
I have also modified the systemd_sevice_toggle function. Before it
looked like it was creating / deleting the file in both child and parent
processes and started / stopped the systemd service in the child
process. Now both actions (creation / deletion of file and start / stop
of service) are done in the child process.
Below are the compiler warnings about incompatible pointer types:
```
menu/menu_setting.c: In function ‘setting_append_list’:
menu/menu_setting.c:18520:58: warning: assignment to ‘change_handler_t’ {aka ‘void (*)(struct rarch_setting *)’} from incompatible pointer type ‘void (*)(void *)’ [-Wincompatible-pointer-types]
18520 | (*list)[list_info->index - 1].change_handler = ssh_enable_toggle_change_handler;
| ^
menu/menu_setting.c:18536:58: warning: assignment to ‘change_handler_t’ {aka ‘void (*)(struct rarch_setting *)’} from incompatible pointer type ‘void (*)(void *)’ [-Wincompatible-pointer-types]
18536 | (*list)[list_info->index - 1].change_handler = samba_enable_toggle_change_handler;
| ^
menu/menu_setting.c:18552:58: warning: assignment to ‘change_handler_t’ {aka ‘void (*)(struct rarch_setting *)’} from incompatible pointer type ‘void (*)(void *)’ [-Wincompatible-pointer-types]
18552 | (*list)[list_info->index - 1].change_handler = bluetooth_enable_toggle_change_handler;
| ^
menu/menu_setting.c:18568:58: warning: assignment to ‘change_handler_t’ {aka ‘void (*)(struct rarch_setting *)’} from incompatible pointer type ‘void (*)(void *)’ [-Wincompatible-pointer-types]
18568 | (*list)[list_info->index - 1].change_handler = localap_enable_toggle_change_handler;
| ^
```
