clk: renesas: r8a77995: Add missing CPEX clock

The R-Car Gen3 HardWare Manual Errata for Rev. 0.80 (Feb 28, 2018) added
the CPEX clock on R-Car D3. This clock can be selected as a clock
source for CMT1 (Compare Match Timer Type 1).

Add the missing clock to the DT bindings header, and implement support
for it in the clock driver.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Stephen Boyd <sboyd@kernel.org>

clk: renesas: r8a77995: Remove non-existent SSP clocks

The R-Car Gen3 HardWare Manual Errata for Rev. 0.80 (Dec 22, 2017, and
Feb 28, 2018) removed the SSPSRC, SSP1, and SSP2 clocks on R-Car D3, as
this SoC does not have a Stream and Security Processor.

As these definitions were never used, they can just be removed.
The freed slots in the DT bindings header must not be reused, though.

Fixes: 714c53aa2e2d6d60 ("clk: renesas: Add r8a77995 CPG Core Clock Definitions")
Fixes: d71e851d82c6cfe5 ("clk: renesas: cpg-mssr: Add R8A77995 support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Stephen Boyd <sboyd@kernel.org>

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 r8a77995 CPG Core Clock Definitions

Add all R-Car D3 Clock Pulse Generator Core Clock Outputs, as listed
in Table 8.2f ("List of Clocks [R-Car D3]") of the R-Car Series, 3rd
Generation Hardware User's Manual (Rev. 0.55, Jun. 30, 2017).

Note that internal CPG clocks (S0, S1, S2, S3, S1C, S3C, SDSRC, and
SSPSRC) are not included, as they are used as internal clock sources
only, and never referenced from DT.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>