[PATCH] mfd: sprd-sc27xx-spi: Fix-up bogus IRQ register offset and mask setting

[Lee Jones]

'i / pdata->num_irqs' always equates to 0 and 'BIT(i % pdata->num_irqs)'
always ends up being BIT(i) here, so make that clearer in the code.  If
the code base needs to support more than 32 IRQs in the future, this will
have to be reworked, but lets just keep it simple for as long as we can.

This fixes the following W=1 warning:

 drivers/mfd/sprd-sc27xx-spi.c:255 sprd_pmic_probe() debug: sval_binop_unsigned: divide by zero

Cc: Orson Zhai <orsonzhai at gmail.com>
Cc: Chunyan Zhang <zhang.lyra at gmail.com>
Cc: Johan Hovold <johan at kernel.org>
Suggested-by: Baolin Wang <baolin.wang7 at gmail.com>
Signed-off-by: Lee Jones <lee.jones at linaro.org>

diff --git a/drivers/mfd/sprd-sc27xx-spi.c b/drivers/mfd/sprd-sc27xx-spi.c
index c305e941e435c..4a1a61e1a86ea 100644
--- a/drivers/mfd/sprd-sc27xx-spi.c
+++ b/drivers/mfd/sprd-sc27xx-spi.c
@@ -251,10 +251,8 @@ static int sprd_pmic_probe(struct spi_device *spi)
                return -ENOMEM;
 
        ddata->irq_chip.irqs = ddata->irqs;
-       for (i = 0; i < pdata->num_irqs; i++) {
-               ddata->irqs[i].reg_offset = i / pdata->num_irqs;
-               ddata->irqs[i].mask = BIT(i % pdata->num_irqs);
-       }
+       for (i = 0; i < pdata->num_irqs; i++)
+               ddata->irqs[i].mask = BIT(i);
 
        ret = devm_regmap_add_irq_chip(&spi->dev, ddata->regmap, ddata->irq,
                                       IRQF_ONESHOT | IRQF_NO_SUSPEND, 0,