[PATCH 2/4] ARM: i.MX6: Riotboard: Add hint how to enable DEBUG_LL

[Sascha Hauer]

It's not obvious which UART to chose when trying to get DEBUG_LL output
from a board. Start improving the situation by adding a comment
describing which options to enable.

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 arch/arm/boards/embest-riotboard/lowlevel.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/boards/embest-riotboard/lowlevel.c b/arch/arm/boards/embest-riotboard/lowlevel.c
index 3aae39f75f70601a0da7b061a5bd2b922a3e1cea..f1b37c2aa00d44ad8a2091abf21584ca531b7794 100644
--- a/arch/arm/boards/embest-riotboard/lowlevel.c
+++ b/arch/arm/boards/embest-riotboard/lowlevel.c
@@ -21,6 +21,10 @@ ENTRY_FUNCTION(start_imx6s_riotboard, r0, r1, r2)
 	imx6_cpu_lowlevel_init();
 
 	if (IS_ENABLED(CONFIG_DEBUG_LL)) {
+		/*
+		 * CONFIG_DEBUG_IMX6Q_UART=y
+		 * CONFIG_DEBUG_IMX_UART_PORT=2
+		 */
 		writel(0x4, 0x020e016c);
 		imx6_ungate_all_peripherals();
 		imx6_uart_setup_ll();

-- 
2.47.3