Add 1-window WindowMMU to Kelvin to support TCM offset

This CL adds an untouchable WindowMMU to Kelvin with a single window
translating addresses 0x00000000 : MemorySize to MemoryRangeStart :
MemoryRangeStart + MemorySize. This is needed in simulation because
Kelvin's software expects memory to begin at address 0x00000000 but
Renode doesn't support multiple address spaces without the use of
MMUs.

Change-Id: I08b7baf071f916f29f62470224e43ab7e7c221d8