opcodes/arm: adjust whitespace in cpsie instruction

While I was working on the disassembler styling for ARM I noticed that
the whitespace in the cpsie instruction was inconsistent with most of
the other ARM disassembly output, the disassembly for cpsie looks like
this:

  cpsie   if,#10

notice there's no space before the '#10' immediate, most other ARM
instructions have a space before each operand.

This commit updates the disassembler to add the missing space, and
updates the tests I found that tested this instruction.