serial: tegra: Remove custom frame size calculation

The number of bits can be calculated using tty_get_frame_size(), no
need for the driver to do it on its own.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220830084925.5608-6-ilpo.jarvinen@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/serial-tegra.c

@@ -1279,7 +1279,6 @@ static void tegra_uart_set_termios(struct uart_port *u,
 	unsigned long flags;
 	unsigned int lcr;
 	unsigned char char_bits;
-	int symb_bit = 1;
 	struct clk *parent_clk = clk_get_parent(tup->uart_clk);
 	unsigned long parent_clk_rate = clk_get_rate(parent_clk);
 	int max_divider = (tup->cdata->support_clk_src_div) ? 0x7FFF : 0xFFFF;
@@ -1306,7 +1305,6 @@ static void tegra_uart_set_termios(struct uart_port *u,
 	termios->c_cflag &= ~CMSPAR;
 
 	if ((termios->c_cflag & PARENB) == PARENB) {
-		symb_bit++;
 		if (termios->c_cflag & PARODD) {
 			lcr |= UART_LCR_PARITY;
 			lcr &= ~UART_LCR_EPAR;
@@ -1319,22 +1317,18 @@ static void tegra_uart_set_termios(struct uart_port *u,
 	}
 
 	char_bits = tty_get_char_size(termios->c_cflag);
-	symb_bit += char_bits;
 	lcr &= ~UART_LCR_WLEN8;
 	lcr |= UART_LCR_WLEN(char_bits);
 
 	/* Stop bits */
-	if (termios->c_cflag & CSTOPB) {
+	if (termios->c_cflag & CSTOPB)
 		lcr |= UART_LCR_STOP;
-		symb_bit += 2;
-	} else {
+	else
 		lcr &= ~UART_LCR_STOP;
-		symb_bit++;
-	}
 
 	tegra_uart_write(tup, lcr, UART_LCR);
 	tup->lcr_shadow = lcr;
-	tup->symb_bit = symb_bit;
+	tup->symb_bit = tty_get_frame_size(termios->c_cflag);
 
 	/* Baud rate. */
 	baud = uart_get_baud_rate(u, termios, oldtermios,