media: rc: keymaps: add missing MODULE_DESCRIPTION to keymaps

When building the modules 'modpost' warns about missing MODULE_DESCRIPTION.

Since almost none of the rc keymap modules have this, it produces a lot of
warnings.

As a first step to fixing all media modules, add this line to all keymaps.
The description should be a human-readable string describing the remote
or the remote controller that the keymap can be used with.

Note that keymaps/rc-cec.c is actually compiled into the rc-core, so that
is the sole keymap source that didn't need this.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sean Young <sean@mess.org>

media: rc: add keymap for Khadas VIM/EDGE remote

Khadas VIM and Edge SBC devices use the same NEC remote device. The
remote includes a mouse button for Android use. This has been mapped
to KEY_MUTE.

Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>