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 common keymap for Dreambox RC10/RC0 and RC20/RC-BT remotes

Add a common keymap for the RC10/RC0 and RC20/RC-BT remotes used with
the Dreambox One and Dreambox Two DVB-S/T boxes. The maps are combined
since the IR codes do not conflict and both boxes have shipped with
both remote designs over time.

Both remote types can be programmed to control TVs, so include non-IR
keys that are used to switch-to or toggle the remote mode:

- DREAM in RC10/RC0 switches to (Dreambox) STB control mode
- TV in RC10/RC0 switches to TV control mode
- MODE in RC20/RC-BT toggles between STB/TV/BT control modes

In the RC20 keymap the Android MIC (voice search) key maps to KEY_HELP
and EXIT is mapped to KEY_ESC to replicate the go-backwards navigation
behaviour in the Android vendor OS that ships on Dreambox devices.

Signed-off-by: Emanuel Strobel <emanuel.strobel@yahoo.com>
Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>