mtd-utils: provide spec file for version 1.2.0

I suggest to add package mtd-utils to rpmforge. This package is available in Fedora. I am using it on el5 i386 and el6 x86_64 CentOS editions.

Provide spec file for version 1.2.0. Spec file comes from Fedora 13.

I had the package built locally for at least 3 years and used mkfs.jffs2
and sumtool utilities on el5 i386 and el6 x86_64. I only verified the
building process of the package in mock for el5 x86_64 and el6 i386.