Rename interrupt unit module instance to 'interrupt_unit'

Original-Author: lekernel
Original-Source: milkymist f061a3098702da3b8a81

     1.1 diff -r e8125a6a3bd8 -r e66ed0e9e2f8 lm32_cpu.v
     1.2 --- a/lm32_cpu.v	Sun Mar 06 19:22:27 2011 +0000
     1.3 +++ b/lm32_cpu.v	Sun Mar 06 19:23:51 2011 +0000
     1.4 @@ -1070,7 +1070,7 @@
     1.5                
     1.6  `ifdef CFG_INTERRUPTS_ENABLED
     1.7  // Interrupt unit
     1.8 -lm32_interrupt interrupt (
     1.9 +lm32_interrupt interrupt_unit (
    1.10      // ----- Inputs -------
    1.11      .clk_i                  (clk_i),
    1.12      .rst_i                  (rst_i),