default-providers: define keymaps virtual runtime provider

default-providers: define keymaps virtual runtime provider

VIRTUAL-RUNTIME_keymaps is defined in busybox init manager and also in
some package groups. Defining distro features in recipes is wrong.
Also this is not directly related to init manager.
So move all these definitions to default-providers.inc

Signed-off-by: Peter Marko <peter.marko@siemens.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>