marvell: uart: a3720: Fix macro name for 6th bit of Status Register

This patch does not change code, it only updates comments and macro name
for 6th bit of Status Register. So TF-A binary stay same.

6th bit of the Status Register is named TX EMPTY and is set to 1 when both
Transmitter Holding Register (THR) or Transmitter Shift Register (TSR) are
empty. It is when all characters were already transmitted.

There is also TX FIFO EMPTY bit in the Status Register which is set to 1
only when THR is empty.

In both console_a3700_core_init() and console_a3700_core_flush() functions
we should wait until both THR and TSR are empty therefore we should check
6th bit of the Status Register.

So current code is correct, just had misleading macro names and comments.
This change fixes this "documentation" issue, fixes macro name for 6th bit
of the Status Register and also updates comments.

Signed-off-by: Pali Rohár <pali@kernel.org>
Change-Id: I19e4e7f53a90bcfb318e6dd1b1249b6cbf81c4d3
diff --git a/drivers/marvell/uart/a3700_console.S b/drivers/marvell/uart/a3700_console.S
index 9a557aa..58dad7a 100644
--- a/drivers/marvell/uart/a3700_console.S
+++ b/drivers/marvell/uart/a3700_console.S
@@ -60,14 +60,14 @@
 	str	w3, [x0, #UART_POSSR_REG]
 
 	/*
-	 * Wait for the TX FIFO to be empty. If wait for 20ms, the TX FIFO is
+	 * Wait for the TX (THR and TSR) to be empty. If wait for 20ms, the TX FIFO is
 	 * still not empty, TX FIFO will reset by all means.
 	 */
 	mov	w1, #20				/* max time out 20ms */
 2:
-	/* Check whether TX FIFO is empty */
+	/* Check whether TX (THR and TSR) is empty */
 	ldr	w3, [x0, #UART_STATUS_REG]
-	and	w3, w3, #UARTLSR_TXFIFOEMPTY
+	and	w3, w3, #UARTLSR_TXEMPTY
 	cmp	w3, #0
 	b.ne	4f
 
@@ -241,10 +241,10 @@
 	 * ---------------------------------------------
 	 */
 func console_a3700_core_flush
-	/* Wait for the TX FIFO to be empty */
+	/* Wait for the TX (THR and TSR) to be empty */
 1:	ldr	w1, [x0, #UART_STATUS_REG]
-	and	w1, w1, #UARTLSR_TXFIFOEMPTY
-	cmp	w1, #UARTLSR_TXFIFOEMPTY
+	and	w1, w1, #UARTLSR_TXEMPTY
+	cmp	w1, #UARTLSR_TXEMPTY
 	b.ne	1b
 	ret
 endfunc console_a3700_core_flush