serial: pmac_zilog: remove unused uart_pmac_port::termios_cache

struct uart_pmac_port contains termios_cache. It is only written and
never read. Remove it as it only occupies space.

Cc: Michael Ellerman <[e-mail]>
Cc: Benjamin Herrenschmidt <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Signed-off-by: Jiri Slaby <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/serial/pmac_zilog.c

···
 
 	pmz_debug("pmz: set_termios()\n");
 
-	memcpy(&uap->termios_cache, termios, sizeof(struct ktermios));
-
 	/* XXX Check which revs of machines actually allow 1 and 4Mb speeds
 	 * on the IR dongle. Note that the IRTTY driver currently doesn't know
 	 * about the FIR mode and high speed modes. So these are unused. For

drivers/tty/serial/pmac_zilog.h

···
 	volatile u8			__iomem *data_reg;
 
 	unsigned char			irq_name[8];
-
-	struct ktermios			termios_cache;
 };
 
 #define to_pmz(p) ((struct uart_pmac_port *)(p))