Adding Leon processor to the SPARC list of processors

[Konrad Eisele]

>> * CONFIG_IU_MUL_LATENCY_2: Implementation options for the integer multiplier.
>>   Type        Implementation              issue-rate/latency
>>   2-clocks    32x32 pipelined multiplier     1/2 
>>   4-clocks    16x16 standard multiplier      4/4
>>   5-clocks    16x16 pipelined multiplier     4/5

I'm not shure how I should model this in gcc. I'm not that familiar with
the gcc internals. Maybe someone could assist me?

>>   GR FPU:      1/4, with FDIV? 16 and FSQRT? 24 cycles,
>>                     non-pipelined on separate unit
>>   GR FPU Lite: 8/8, with FDIVS/FDIVD/FSQRTS/FSQRTD 31/57/46/57 cycles,
>>                     non-pipelined on same unit

I could add a tune option that would switch the processor cost  struct for FPU/FPU-lite.

-- Greetings Konrad