clk/aspeed: Add debug message when clock fails

A common message across platforms that prints the clock number.

Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/drivers/clk/aspeed/clk_ast2500.c b/drivers/clk/aspeed/clk_ast2500.c
index a1b4496..dcf2995 100644
--- a/drivers/clk/aspeed/clk_ast2500.c
+++ b/drivers/clk/aspeed/clk_ast2500.c
@@ -173,6 +173,7 @@
 		rate = ast2500_get_uart_clk_rate(priv->scu, 5);
 		break;
 	default:
+		debug("%s: unknown clk %ld\n", __func__, clk->id);
 		return -ENOENT;
 	}
 
@@ -438,6 +439,7 @@
 		new_rate = ast2500_configure_d2pll(priv->scu, rate);
 		break;
 	default:
+		debug("%s: unknown clk %ld\n", __func__, clk->id);
 		return -ENOENT;
 	}
 
@@ -480,6 +482,7 @@
 		ast2500_configure_d2pll(priv->scu, D2PLL_DEFAULT_RATE);
 		break;
 	default:
+		debug("%s: unknown clk %ld\n", __func__, clk->id);
 		return -ENOENT;
 	}