ASoC: fsi: Remove obsolete sh_fsi2 platform_device_id entry

Since the removal of the r8a7740 legacy board code in commit
1fa59bda ("ARM: shmobile: Remove legacy board code for
Armadillo-800 EVA"), all former users of the "sh_fsi2" platform device
name are only supported in generic DT-only ARM multi-platform builds.
The driver doesn't need to match platform devices by name anymore, hence
remove the corresponding platform_device_id entry.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>