dt-bindings: clock: renesas: Convert to SPDX identifiers

This patch updates license to use SPDX-License-Identifier
instead of verbose license text on Renesas related headers.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

clk: renesas: Add r8a7743 CPG Core Clock Definitions

Add macros usable by the device tree sources to reference the R8A7743 CPG
clocks by index. The data comes from Table 7.2b in revision 1.00 of the
RZ/G Series User's Manual.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>