build: correct package dependencies

build: correct package dependencies

The wscript_build files convey what header files belong to which
logical package. For example,

    # lib/util/wscript_build:
    bld.SAMBA_LIBRARY('samba-util',
                      public_headers='... data_blob.h ...'

    # auth/credentials/wscript_build:
    bld.SAMBA_LIBRARY('samba-credentials',
                      public_headers='credentials.h',

Now, credentials.h #includes <util/data_blob.h> and therefore,
samba-credentials.pc must have a Requires: samba-util.

Similarly for other parts.

Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Reviewed-by: David Disseldorp <ddiss@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>