tinyalsa: new package

[Thomas:
 - remove 'default n', since it's the default
 - add dependency on !BR2_PREFER_STATIC_LIB since the Makefile always
   builds a shared library.
 - move from Audio/video applications to Libraries -> Audio.]

Signed-off-by: Maxime Hadjinlian <maxime.hadjinlian@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>