dt_get_virtual_reg
if (dt_get_virtual_reg(devp, vreg, 2) < 2)
if (dt_get_virtual_reg(parent, &cpcr, 1) < 1)
if (dt_get_virtual_reg(muram, &muram_addr, 1) < 1)
if (dt_get_virtual_reg(devp, &psc, 1) < 1)
if (dt_get_virtual_reg(devp, (void **)®_base, 1) < 1) {
int dt_get_virtual_reg(void *node, void **addr, int nres);