mxs_spi: Return proper timeout error

Instead of returning -1, it is preferred to return -ETIMEDOUT in case of timeouts.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>

drivers/spi/mxs_spi.c

@@ -162,7 +162,7 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
 		if (mx28_wait_mask_set(&ssp_regs->hw_ssp_ctrl0_reg,
 			SSP_CTRL0_RUN, MXS_SPI_MAX_TIMEOUT)) {
 			printf("MXS SPI: Timeout waiting for start\n");
-			return -1;
+			return -ETIMEDOUT;
 		}
 
 		if (tx)
@@ -174,7 +174,7 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
 			if (mx28_wait_mask_clr(&ssp_regs->hw_ssp_status_reg,
 				SSP_STATUS_FIFO_EMPTY, MXS_SPI_MAX_TIMEOUT)) {
 				printf("MXS SPI: Timeout waiting for data\n");
-				return -1;
+				return -ETIMEDOUT;
 			}
 
 			*rx = readl(&ssp_regs->hw_ssp_data);
@@ -184,7 +184,7 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
 		if (mx28_wait_mask_clr(&ssp_regs->hw_ssp_ctrl0_reg,
 			SSP_CTRL0_RUN, MXS_SPI_MAX_TIMEOUT)) {
 			printf("MXS SPI: Timeout waiting for finish\n");
-			return -1;
+			return -ETIMEDOUT;
 		}
 	}