MIPS: Netlogic: early console fix

In prom_putchar(), wait for just the TX empty bit to clear in the
UART LSR.
Signed-off-by: NJayachandran C <jayachandranc@netlogicmicro.com>
Cc: linux-mips@linux-mips.org
Cc: Florian Fainelli <florian@openwrt.org>
Patchwork: https://patchwork.linux-mips.org/patch/4112/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/netlogic/common/earlycons.c

@@ -54,7 +54,7 @@ void prom_putchar(char c)
 #elif defined(CONFIG_CPU_XLR)
 	uartbase = nlm_mmio_base(NETLOGIC_IO_UART_0_OFFSET);
 #endif
-	while (nlm_read_reg(uartbase, UART_LSR) == 0)
+	while ((nlm_read_reg(uartbase, UART_LSR) & UART_LSR_THRE) == 0)
 		;
 	nlm_write_reg(uartbase, UART_TX, c);
 }