lib/math: Add int_log test suite

lib/math: Add int_log test suite

This commit introduces KUnit tests for the intlog2 and intlog10
functions, which compute logarithms in base 2 and base 10, respectively.
The tests cover a range of inputs to ensure the correctness of these
functions across common and edge cases.

Signed-off-by: Bruno Sobreira França <brunofrancadevsec@gmail.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Link: https://lore.kernel.org/r/20241202075545.3648096-3-davidgow@google.com
Signed-off-by: Kees Cook <kees@kernel.org>