LinuxKPI: Add ida_alloc_min()

ida_alloc_min() allocates an unused ID. between min and INT_MAX.

While here allow end parameter of ida_simple_get() be larger than
INT_MAX. Linux caps the value to INT_MAX.

Sponsored by: Serenity Cyber Security, LLC
Reviewers: manu, bz
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D42806