tty: serial: meson: Make some bit of the REG5 register writable

Make the internal clock source mux and divider writeable, allowing the
uart to deviate from the settings intially applied by the ROMCode and
using the most appropriate clocks.
Signed-off-by: Yu Tu <yu.tu@amlogic.com>
Link: https://lore.kernel.org/r/20220225073922.3947-5-yu.tu@amlogic.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/meson_uart.c

@@ -686,7 +686,7 @@ static int meson_uart_probe_clocks(struct uart_port *port)
 						CLK_SET_RATE_NO_REPARENT,
 						port->membase + AML_UART_REG5,
 						26, 2,
-						CLK_DIVIDER_READ_ONLY,
+						CLK_DIVIDER_ROUND_CLOSEST,
 						xtal_div_table, NULL);
 	if (IS_ERR(hw))
 		return PTR_ERR(hw);
@@ -708,7 +708,7 @@ static int meson_uart_probe_clocks(struct uart_port *port)
 					CLK_SET_RATE_PARENT,
 					port->membase + AML_UART_REG5,
 					24, 0x1,
-					CLK_MUX_READ_ONLY,
+					CLK_MUX_ROUND_CLOSEST,
 					&use_xtal_mux_table, NULL);
 
 	if (IS_ERR(hw))