refactor(st): configure baudrate for UART programmer

Add the possibility to configure the UART baudrate; reused the
console configuration, defined in STM32MP_UART_BAUDRATE.

The default value remains 115200.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Change-Id: Ifcf2b36e8ac929265405bc88e824ee78be3b5bbb
diff --git a/plat/st/common/stm32cubeprogrammer_uart.c b/plat/st/common/stm32cubeprogrammer_uart.c
index 9520703..d004dcf 100644
--- a/plat/st/common/stm32cubeprogrammer_uart.c
+++ b/plat/st/common/stm32cubeprogrammer_uart.c
@@ -486,7 +486,7 @@
 
 /* Init UART: 115200, 8bit 1stop parity even and enable FIFO mode */
 const struct stm32_uart_init_s init = {
-	.baud_rate = U(115200),
+	.baud_rate = STM32MP_UART_BAUDRATE,
 	.word_length = STM32_UART_WORDLENGTH_9B,
 	.stop_bits = STM32_UART_STOPBITS_1,
 	.parity = STM32_UART_PARITY_EVEN,