tools/syz-bisect: use kernel configs from configuration file
tools/syz-bisect: use kernel configs from configuration file

Currently syz-bisect is expecting to find kernel.config and
kernel_baseline.config from given crashdir. Unify with syz-ci
and use configuration files from bisect config file.

xairy/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller