board: arm64: fvp_baser_aemv8r_smp: Increase CONFIG_MAX_THREAD_BYTES

Increase CONFIG_MAX_THREAD_BYTES to 3 to fix the build issue on
tests/drivers/build_all/modem/ test case.

Signed-off-by: Jaxson Han <jaxson.han@arm.com>
Change-Id: I6a26955bdd7e8b176894fa8246aec63a3a3db05f
(cherry picked from commit a483828d46a37630f1819f62be689a3d7c5409a7)
1 file changed