PX4-NuttX/nuttx branch test: px4-master_auto_rebase

NuttX:
 - https://github.com/PX4-NuttX/nuttx/tree/px4-master_auto_rebase
 - PX4/NuttX@ef3ed74

Changes from PX4-NuttX/nuttx (PX4/NuttX@0ac630e) in current PX4/master (9151351)
PX4/NuttX@0ac630e...ef3ed74

ef3ed74 (HEAD, origin/px4-master_auto_rebase) [PX4: WIP] Fix transmission status handling in the serial interrupt
0b984d9 [PX4: REJECTED] cstdint fix
6c98c8e [PX4: REJECTED] add math.h
0340db9 [PX4: WIP] Jenkinsfile
9f68205 (origin/master) Merged in masayuki2009/nuttx.nuttx/termios_branch (pull request #655)
15e60de configs/nucleo-144:  Divide a long line.
083c1ae drivers/audio: Fix some DEBUGASSERTs and compile failures.
7e78dee configs/sabre-6quad:  Update README.
05ad720 configs/imxrt1050-evk:  Add knsh configuration.. PROTECTED mode NSH build.
8d73337 Trivial coding standard fix.

Apps:
 - https://github.com/PX4-NuttX/apps/tree/px4-master_auto_rebase
 - PX4/NuttX-apps@462c1c1

Changes from PX4-NuttX/apps (PX4/NuttX-apps@7e2f17d) in current PX4/master (9151351)
PX4/NuttX-apps@7e2f17d...462c1c1

462c1c1 (HEAD -> px4-master_auto_rebase, origin/px4-master_auto_rebase) [REJECTED] add-var-expansion-in-nsh-parse.patch
e4a30d5 (origin/master) apps/Make.defs:  Simplify last fix
bf23277 apps/Make.defs:  Fix an error introduced with recent chagne.  MKKCONFIG may not be defined resulting in failure to create apps/Kconfig.
36e04b3 apps/examples/gps:  Add GPS example using MINMEA lib
6aad29e apps/gpsutils/minmea: Include wchar.h in minmea.c file to fix wint_t error
301fe28 Merge branch 'master' of bitbucket.org:nuttx/apps
67e6e33 Merged in masayuki2009/nuttx.apps/taskset_command (pull request #140)
c36a5c1 apps/examples/ostest:  Signal handling tests should use the same configurable stack size as used in other tests, not PTHREAD_STACK_DEFAULT.
0c867bc Merged in MarcoKrahl/apps/ltdc (pull request #139)
c6697c1 Merged in bkueng/nuttx-apps (pull request #138)