fix(st-uart): correctly fill BRR register

To get the nearest divisor for BRR register, we use:
Divisor =  (Uart clock + (baudrate / 2)) / baudrate
But lsl was wrongly used instead of lsr to have the division by 2.

Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Change-Id: Iedcc3ccdb4cf8268012e82a66df2a9ec48fc1d79
diff --git a/drivers/st/uart/aarch32/stm32_console.S b/drivers/st/uart/aarch32/stm32_console.S
index 2b8879a..256e7a3 100644
--- a/drivers/st/uart/aarch32/stm32_console.S
+++ b/drivers/st/uart/aarch32/stm32_console.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2021, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2022, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -67,7 +67,7 @@
 	bic	r3, r3, #USART_CR2_STOP
 	str	r3, [r0, #USART_CR2]
 	/* Divisor =  (Uart clock + (baudrate / 2)) / baudrate */
-	lsl	r3, r2, #1
+	lsr	r3, r2, #1
 	add	r3, r1, r3
 	udiv	r3, r3, r2
 	str	r3, [r0, #USART_BRR]