spi: sirf: enable RX_IO_DMA_INT interrupt

commit f2a08b40 upstream.

in spi interrupt handler, we need check RX_IO_DMA status to ensure
rx fifo have received the specify count data.

if not set, the while statement in spi isr function will keep loop,
at last, make the kernel hang.

[The code is actually there in the interrupt handler but apparently it
needs the interrupt unmasking so the handler sees the status -- broonie]
Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/spi/spi-sirf.c

@@ -438,7 +438,8 @@ static void spi_sirfsoc_pio_transfer(struct spi_device *spi,
 			sspi->tx_word(sspi);
 		writel(SIRFSOC_SPI_TXFIFO_EMPTY_INT_EN |
 			SIRFSOC_SPI_TX_UFLOW_INT_EN |
-			SIRFSOC_SPI_RX_OFLOW_INT_EN,
+			SIRFSOC_SPI_RX_OFLOW_INT_EN |
+			SIRFSOC_SPI_RX_IO_DMA_INT_EN,
 			sspi->base + SIRFSOC_SPI_INT_EN);
 		writel(SIRFSOC_SPI_RX_EN | SIRFSOC_SPI_TX_EN,
 			sspi->base + SIRFSOC_SPI_TX_RX_EN);