The expressions for the `micropy_hw_hse_value` etc variables may contain
parenthesis, eg `micropy_hw_hse_value = ((25) * 1000000)`. To handle such
a case, simplify the regex and always use `eval(found)` to evaluate the
expression.
Signed-off-by: Damien George <damien@micropython.org>
3c1722e705