clk: renesas: Make CLK_R9A06G032 invisible

clk: renesas: Make CLK_R9A06G032 invisible

When configuring a kernel including support for Renesas ARM/ARM64 Socs,
but excluding support for the RZ/N1D SoC, the user is always asked about
the RZ/N1D clock driver.  As this driver is already auto-selected when
building a kernel including support for the RZ/N1D SoC, there is no need
to make the CLK_R9A06G032 symbol visible, unless compile-testing.

Align the symbol description with the other symbols.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/4f3d30c730c30546f702715ffc648922a8156703.1628672649.git.geert+renesas@glider.be