spi: rspi: Remove obsolete platform_device_id entries

Since commits 05104c26 ("ARM: shmobile: r7s72100: genmai: Remove
legacy board file") and a483dcbf

 ("ARM: shmobile: lager: Remove
legacy board support", RZ/A1 and R-Car Gen2 SoCs are only supported in
generic DT-only ARM multi-platform builds.  The driver doesn't need to
match platform devices by name anymore for these platforms, hence remove
the corresponding platform_device_id entries.

The platform_device_id entry for "rspi" is retained, as it is used by
the SH7757 platform, which hasn't been converted to DT yet.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Link: https://lore.kernel.org/r/20191211131553.23960-1-geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>