qapi: Drop redundant documentation of inherited members

qapi: Drop redundant documentation of inherited members

Documentation generated for SchemaInfo looks like

    The members of "SchemaInfoBuiltin" when "meta-type" is ""builtin""
    The members of "SchemaInfoEnum" when "meta-type" is ""enum""
    The members of "SchemaInfoArray" when "meta-type" is ""array""
    The members of "SchemaInfoObject" when "meta-type" is ""object""
    The members of "SchemaInfoAlternate" when "meta-type" is ""alternate""
    The members of "SchemaInfoCommand" when "meta-type" is ""command""
    The members of "SchemaInfoEvent" when "meta-type" is ""event""
    Additional members depend on the value of "meta-type".

The last line became redundant when commit 88f63467c57 (qapi2texi:
Generate reference to base type members) added the lines preceding it.
Drop it.

BlockdevOptions has the same issue.  Drop

    Remaining options are determined by the block driver.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240129115008.674248-2-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>