dt-bindings: clock: ti-sci: Fix incorrect usage of headers

The clock consumer usage description was erroneously referring to
couple of dt-binding headers that are no longer valid. The definition
and/or usage of these headers is incorrect and the only file present
at the moment, dt-bindings/soc/k2g.h is also being cleaned up. The
examples in this binding were updated properly, but the update to
description was missed out. So, fix this.

Fixes: 8f306cfe4383 ("Documentation: dt: Add TI SCI clock driver")
Signed-off-by: Suman Anna <[e-mail]>
Signed-off-by: Rob Herring <[e-mail]>

Documentation/devicetree/bindings/clock/ti,sci-clk.txt

···
 - compatible: Must be "ti,k2g-sci-clk"
 - #clock-cells: Shall be 2.
   In clock consumers, this cell represents the device ID and clock ID
-  exposed by the PM firmware. The assignments can be found in the header
-  files <dt-bindings/genpd/<soc>.h> (which covers the device IDs) and
-  <dt-bindings/clock/<soc>.h> (which covers the clock IDs), where <soc>
-  is the SoC involved, for example 'k2g'.
+  exposed by the PM firmware. The list of valid values for the device IDs
+  and clocks IDs for 66AK2G SoC are documented at
+  http://processors.wiki.ti.com/index.php/TISCI#66AK2G02_Data
 
 Examples:
 --------