media: rc: remove tango ir driver and keymap

The tango platform was removed, so the driver is no longer needed.

Cc: Marc Gonzalez <marc.w.gonzalez@free.fr>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>