The CCM_CBCMR register (address 0x02C4018) has different meaning
between the i.MX6 Quad/Dual and the i.MX6 Solo/DualLite.
Compared to the i.MX6 Quad/Dual, the CCM_CBCMR register in the
i.MX6 Solo/DualLite doesn't have a gpu3d_shader configuration and
moves the gpu2_core configuration at that place.
Handle these i.MX6 Quad/Dual vs. i.MX6 Solo/DualLite clock differences
by using cpu_is_mx6dl().