rockchip: rk3308: fix rockchip_dnl_key_pressed() on roc-cc

Commit 6aa4fe3912 ("dm: core: Rename and fix uclass_get_by_name_len()")
changed uclass_get_device_by_name() to an exact match when previously it
behaved as a prefix match.

The roc-cc code relied on this prefix match by only specifying part of
the device name.  Fix this by using the full name including the address.

Signed-off-by: John Keeping <john@metanate.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/board/firefly/firefly-rk3308/roc_cc_rk3308.c b/board/firefly/firefly-rk3308/roc_cc_rk3308.c
index 28dcc2a..bdf3cc0 100644
--- a/board/firefly/firefly-rk3308/roc_cc_rk3308.c
+++ b/board/firefly/firefly-rk3308/roc_cc_rk3308.c
@@ -70,7 +70,7 @@
 {
 	unsigned int val;
 
-	if (adc_channel_single_shot("saradc", 1, &val)) {
+	if (adc_channel_single_shot("saradc@ff1e0000", 1, &val)) {
 		printf("%s read adc key val failed\n", __func__);
 		return false;
 	}