maintainers: set git tree for test applications

maintainers: set git tree for test applications

Changes on the main test applications should be considered against
subtrees where most of the API changes and development happen:
- testpmd goes through dpdk-next-net as it is mainly about ethdev,
- dpdk-test-compress-perf goes through dpdk-next-crypto since the
  compress API goes through this tree,
- dpdk-test-crypto-perf through dpdk-next-crypto,
- dpdk-test-eventdev through dpdk-next-eventdev,

Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Jerin Jacob <jerinj@marvell.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Andrew Rybchenko <arybchenko@solarflare.com>
Acked-by: Akhil Goyal <akhil.goyal@nxp.com>