pinctrl: sh-pfc: Remove obsolete sh73a0 platform_device_id entry

Since the removal of the sh73a0 legacy SoC code in commit
9a986398 ("ARM: shmobile: Remove legacy SoC code for SH-Mobile
AG5"), sh73a0 is 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>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>