soc/amd/picasso: rename PICASSO_UART Kconfig option

The PICASSO_UART Kconfig option is about using the internal MMIO UART
controllers in Picasso for console, so rename it to PICASSO_CONSOLE_UART

Change-Id: I38ac9ee96af826fe49307b4d0e055a43fcbd4334
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/42429
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-by: Raul Rangel <rrangel@chromium.org>

src/soc/amd/picasso/southbridge.c

@@ -152,7 +152,7 @@ void fch_pre_init(void)
 	 */
 	clear_uart_legacy_config();
 
-	if (CONFIG(PICASSO_UART))
+	if (CONFIG(PICASSO_CONSOLE_UART))
 		set_uart_config(CONFIG_UART_FOR_CONSOLE);
 }