Use the SoC-specific CPG/MSSR include file to allow future use of
R8A77990_CLK_* symbols.
Replace the hardcoded power domain indices by R8A77990_PD_* symbols.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>