MIPS: OCTEON: program L2C_CTL on CNF71XX too

Since commit bd978130307c ("MIPS: OCTEON: program L2C_CTL, not L2C_CFG, on OCTEON II"), cvmx_helper_initialize_packet_io_global() writes L2C_CTL instead of L2C_CFG, because L2C_CFG does not exist on OCTEON II and writing it hangs a CN6335. The test is OCTEON_CN6XXX, which leaves the CNF71XX - also an OCTEON II, as OCTEON_IS_OCTEON2() and the rest of this file treat it - writing the register that commit says is not there.

Use OCTEON_IS_OCTEON2(). OCTEON III (CN7XXX) still takes the L2C_CFG path, as before: I have no such part and do not know which register it wants.

---
Found by the Sashiko review bot on the original series. By inspection
only: I have no CNF71XX board to test on. The Fixes: hash is the one in mips-next.

index 107b1be..c02448b 100644
@@ -1028,7 +1028,7 @@ int cvmx_helper_initialize_packet_io_global(void)
 	 * to the cores. This avoids conditions where IO blocks might
 	 * be starved under very high L2 loads.
 	 */
-	if (OCTEON_IS_MODEL(OCTEON_CN6XXX)) {
+	if (OCTEON_IS_OCTEON2()) {
 		union cvmx_l2c_ctl l2c_ctl;
 
 		l2c_ctl.u64 = cvmx_read_csr(CVMX_L2C_CTL);