tty: serial: mpc52xx_uart: make rx/tx hooks return unsigned, part II.

The below commit changed types of some hooks in struct psc_ops. It also
changed the types of the functions which are referenced in the instances
of the above struct.

However the commit did so only for CONFIG_PPC_MPC52xx, but not for
CONFIG_PPC_MPC512x. This results in build errors like:
  mpc52xx_uart.c:static unsigned int mpc52xx_psc_raw_tx_rdy(struct uart_port *port)
  mpc52xx_uart.c:static int mpc512x_psc_raw_tx_rdy(struct uart_port *port)
                        ^^^
  mpc52xx_uart.c:static int mpc5125_psc_raw_tx_rdy(struct uart_port *port)
                        ^^^

Therefore, fix the latter case now too.

Fixes: 18662a1d

 (tty: serial: mpc52xx_uart: make rx/tx hooks return unsigned)
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220404055122.31194-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>