clk: renesas: r8a774a1: Add TMU clock

This patch adds the TMU clocks to the R8A774A1 SoC.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>