MIPS: OCTEON: Set proper UART clock in internal device trees.

Following patch to use generic 8250 drivers will need proper clock
information.  So when using the internal device tree, populate the
"clock-frequency" property with the correct value.
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: Jamie Iles <jamie@jamieiles.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/5515/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/cavium-octeon/octeon-platform.c

@@ -490,8 +490,15 @@ int __init octeon_prune_device_tree(void)
 
 		if (alias_prop) {
 			uart = fdt_path_offset(initial_boot_params, alias_prop);
-			if (uart_mask & (1 << i))
+			if (uart_mask & (1 << i)) {
+				__be32 f;
+
+				f = cpu_to_be32(octeon_get_io_clock_rate());
+				fdt_setprop_inplace(initial_boot_params,
+						    uart, "clock-frequency",
+						    &f, sizeof(f));
 				continue;
+			}
 			pr_debug("Deleting uart%d\n", i);
 			fdt_nop_node(initial_boot_params, uart);
 			fdt_nop_property(initial_boot_params, aliases,