basic_mmio_gpio: allow overriding number of gpio

Some platforms may have a number of GPIO that is less than the register
width of the peripheral.

Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/include/linux/basic_mmio_gpio.h b/include/linux/basic_mmio_gpio.h
index 198087a..f23ec73 100644
--- a/include/linux/basic_mmio_gpio.h
+++ b/include/linux/basic_mmio_gpio.h
@@ -15,6 +15,7 @@
 
 struct bgpio_pdata {
 	int base;
+	int ngpio;
 };
 
 #endif /* __BASIC_MMIO_GPIO_H */