Fix random.ko module.

• Remove duplicated sources between standard part of the kernel and module. In particular, it caused duplicated lock initialization and sysctl registration, both having bad consequences.
• Add missed source files to module.
• Static part of the kernel provides randomdev module, not random_adaptors. Correct dependencies.
• Use cdev modules declaration macros.

Approved by: secteam (delphij)
Reviewed by: markm