clk: renesas: r7s9210: Distinguish clocks by clock type

When registering a clock, its type should be devised from the clock's
type member, not from its id member.
Merge the two checks for the main clock, to improve readability.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/7e61ea78e9919148e73867088ccbc3509364952e.1740126560.git.geert+renesas@glider.be