spi: core: Ignore unsupported spi-[tr]x-bus-width property values

Rejecting unsupported values of spi-tx-bus-width and spi-rx-bus-width
may break compatibility with future DTs. Just ignore them, falling back
to Single SPI Transfers.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/spi/spi.c

@@ -1247,11 +1247,10 @@ static void of_register_spi_devices(struct spi_master *master)
 				spi->mode |= SPI_TX_QUAD;
 				break;
 			default:
-				dev_err(&master->dev,
-					"spi-tx-bus-width %d not supported\n",
-					value);
-				spi_dev_put(spi);
-				continue;
+				dev_warn(&master->dev,
+					 "spi-tx-bus-width %d not supported\n",
+					 value);
+				break;
 			}
 		}
 
@@ -1266,11 +1265,10 @@ static void of_register_spi_devices(struct spi_master *master)
 				spi->mode |= SPI_RX_QUAD;
 				break;
 			default:
-				dev_err(&master->dev,
-					"spi-rx-bus-width %d not supported\n",
-					value);
-				spi_dev_put(spi);
-				continue;
+				dev_warn(&master->dev,
+					 "spi-rx-bus-width %d not supported\n",
+					 value);
+				break;
 			}
 		}