sifive/hifive-unleashed: Drop unneeded console_tx_flush()

Every printk() call already does console_tx_flush()
so there should not be anything in transmit buffer
when we return from console_init().

Change-Id: Iff2927c02d2c8031907620a056782bb014f20162
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/31369
Reviewed-by: Xiang Wang <wxjstz@126.com>
Reviewed-by: Philipp Hug <philipp@hug.cx>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/sifive/hifive-unleashed/romstage.c

@@ -27,12 +27,6 @@ void main(void)
 
 	/* TODO: Follow Section 6.3 (FSBL) of the FU540 manual */
 
-	/*
-	 * Flush console before changing clock/UART divisor to prevent garbage
-	 * being printed.
-	 */
-	console_tx_flush();
-
 	clock_init();
 
 	// re-initialize UART