omgps: Fix build with glib-2.0 > 2.35

Fix errors like

| src/main.c: In function 'main':
| src/main.c:490:2: error: 'g_type_init' is deprecated (declared at
/builds1/angstrom/build/tmp-angstrom_next-eglibc/sysroots/qemuarm/usr/include/glib-2.0/gobject/gtype.h:669)
[-Werror=deprecated-declarations]
|   g_type_init();
|   ^
| cc1: all warnings being treated as errors
| make[1]: *** [omgps-main.o] Error 1

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>