buildroot

micropython-lib: needs pcre

The micropython libs load libpcre dynamically using the foreign function
interface (libffi). Without pcre the build will succeed but at run time
anything that uses the 're' module will have issues.

Signed-off-by: Chris Packham <judge.packham@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>