drm/amd/display: Fix kernel panic by dal_gpio_open() error

Currently both error code paths handled in dal_gpio_open_ex() issues
ASSERT_CRITICAL(), and this leads to a kernel panic unnecessarily if
CONFIG_KGDB is enabled.  Since basically both are non-critical errors
and can be recovered, drop those assert calls and use a safer one,
BREAK_TO_DEBUGGER(), for allowing the debugging, instead.

BugLink: https://bugzilla.opensuse.org/show_bug.cgi?id=1177973
Cc: <stable@vger.kernel.org>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/gpio/gpio_base.c

@@ -63,13 +63,13 @@ enum gpio_result dal_gpio_open_ex(
 	enum gpio_mode mode)
 {
 	if (gpio->pin) {
-		ASSERT_CRITICAL(false);
+		BREAK_TO_DEBUGGER();
 		return GPIO_RESULT_ALREADY_OPENED;
 	}
 
 	// No action if allocation failed during gpio construct
 	if (!gpio->hw_container.ddc) {
-		ASSERT_CRITICAL(false);
+		BREAK_TO_DEBUGGER();
 		return GPIO_RESULT_NON_SPECIFIC_ERROR;
 	}
 	gpio->mode = mode;