dt-bindings: bcm283x: Fix register ranges of bcm2835-i2s

Since 517e7a15 ("ASoC: bcm2835: move to use the clock framework")
the bcm2835-i2s requires a clock as DT property. Unfortunately
the necessary DT change has never been applied. While we are at it
also fix the first PCM register range to cover the PCM_GRAY register.

This patch only fixes the affected dt-bindings.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Eric Anholt <eric@anholt.net>