Allow integer immediate for VFP vmov instructions.
This patch fixes the case where you want to use an integer value the
floating point immediate to a VFP vmov instruction such as
vmovmi.f32 s27, #11.
If the immediate is not a float we convert it and copy it's representation
into the imm field and then carry on validating as if we originally entered
a floating point immediate.
The is considered a QoL improvement for hand assembly writers and allows more
code portability between assembler.