spi: sprd: Fix the incorrect SPI register

The original code used an incorrect SPI register to initialize the SPI
controller in sprd_spi_init_hw(), thus fix it.

Fixes: e7d973a3 ("spi: sprd: Add SPI driver for Spreadtrum SC9860")
Signed-off-by: Huanpeng Xin <huanpeng.xin@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Link: https://lore.kernel.org/r/b4f7f89ec0fdc595335687bfbd9f962213bc4a1d.1575443510.git.baolin.wang7@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-sprd.c

@@ -678,7 +678,7 @@ static int sprd_spi_init_hw(struct sprd_spi *ss, struct spi_transfer *t)
 	if (d->unit != SPI_DELAY_UNIT_SCK)
 		return -EINVAL;
 
-	val = readl_relaxed(ss->base + SPRD_SPI_CTL7);
+	val = readl_relaxed(ss->base + SPRD_SPI_CTL0);
 	val &= ~(SPRD_SPI_SCK_REV | SPRD_SPI_NG_TX | SPRD_SPI_NG_RX);
 	/* Set default chip selection, clock phase and clock polarity */
 	val |= ss->hw_mode & SPI_CPHA ? SPRD_SPI_NG_RX : SPRD_SPI_NG_TX;