Currently PSA backends cannot use other backends because the necessary
definitions are defined in a single big header file. This prevents us
from creating a generic HMAC backend based on the available hash
backends, as the hash context struct is not available when defining the
HMAC context struct.
Fix this by spliting the headers into separate files. This makes it
possible us use the hash context definitions without pulling in the
remaining context definitions.
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
