Add bit-field macros

Arm architectural documentation typically defines bit-fields as
`[msb,lsb]` and single-bit fields as `[bit]`. For clarity it would be
helpful if we could define fields in the same way.

Add helpers so that we can do so, along with helper to extract/insert
bit-field values.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <>
Reviewed-by: Andre Przywara <>
1 file changed