The simple-card driver currently hard-codes the clk_id parameter in
snd_soc_dai_set_sysclk() to 0. Make this configrable for both CPU and
codec dai sub-nodes.

This still has the limitation that only one clk_id can be configured, but it
should help some more platforms to use simple-card in favor to a more
specific machine driver.

Signed-off-by: Daniel Mack <daniel@zonque.org>
---
 Documentation/devicetree/bindings/sound/simple-card.txt |  3 +++
 include/sound/simple_card_utils.h                       |  1 +
 sound/soc/generic/simple-card-utils.c                   |  3 +++
 sound/soc/generic/simple-card.c                         | 10 ++++++----
 4 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/sound/simple-card.txt b/Documentation/devicetree/bindings/sound/simple-card.txt
index a4c72d09cd45..c8d268285a9e 100644
--- a/Documentation/devicetree/bindings/sound/simple-card.txt
+++ b/Documentation/devicetree/bindings/sound/simple-card.txt

@@ -94,6 +94,9 @@ Optional CPU/CODEC subnodes properties:
 - system-clock-direction-out		: specifies clock direction as 'out' on
 					  initialization. It is useful for some aCPUs with
 					  fixed clocks.
+- system-clock-index			: index of the system clock to use when
+					  the mclk frequency is on the CPU/CODEC
+					  DAI. Defaults to 0.