dt/bindings: bcm2835: correct description for DMA-int

Interrupt DMA11 is the shared interrupt for DMA channels 11 to 14
Interrupt DMA12 is the shared interrupt triggering for any DMA channel
(this also includes DMA channel 15)
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Acked-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/interrupt-controller/brcm,bcm2835-armctrl-ic.txt

@@ -71,8 +71,8 @@ Bank 1:
 24: DMA8
 25: DMA9
 26: DMA10
-27: DMA11
-28: DMA12
+27: DMA11-14 - shared interrupt for DMA 11 to 14
+28: DMAALL - triggers on all dma interrupts (including chanel 15)
 29: AUX
 30: ARM
 31: VPUDMA