PX4-NuttX/nuttx branch test: px4-master_auto_rebase

NuttX:
 - https://github.com/PX4-NuttX/nuttx/tree/px4-master_auto_rebase
 - PX4/NuttX@3d019df

Changes from PX4-NuttX/nuttx (PX4/NuttX@8957a02) in current PX4/master (0928112)
PX4/NuttX@8957a02...3d019df

3d019df (HEAD, origin/px4-master_auto_rebase) [PX4: WIP] Fix transmission status handling in the serial interrupt
ab04315 [PX4: REJECTED] cstdint fix
f7e68a8 [PX4: REJECTED] add math.h
3e1516a [PX4: WIP] Jenkinsfile
d755b07 (origin/master) drivers/analog:  Add driver for digital to analog converted DAC7571.
8810002 configs/metro-m4:  Update README.  I have bricked by board 8(
1d70e7f Revert "drivers/input/ft5x06.c:  Back out part of last PR.  I think that is correct to detach the interrupt handler when the drivers is unlinked."
b79e6b9 drivers/input/ft5x06.c:  Back out part of last PR.  I think that is correct to detach the interrupt handler when the drivers is unlinked.
18ca531 Merged in plwm/nuttx/stm32f746g-disco-touchscreen (pull request #701)
5dec4a6 configs/metro-m4:  Corrrect SERCOM3 pin configuration

Apps:
 - https://github.com/PX4-NuttX/apps/tree/px4-master_auto_rebase
 - PX4/NuttX-apps@b1d4755

Changes from PX4-NuttX/apps (PX4/NuttX-apps@36806ba) in current PX4/master (0928112)
PX4/NuttX-apps@36806ba...b1d4755

b1d4755 (HEAD -> px4-master_auto_rebase, origin/px4-master_auto_rebase) [REJECTED] add-var-expansion-in-nsh-parse.patch
d9cb917 (origin/master) Merged in masayuki2009/nuttx.apps/refactor_nxplayer (pull request #149)
822291b apps/fsutils/mkfatfs:  Add some comments.  Clean up some coding style issues.
d365707 Add definitions for the FAT boot record (FBR).
6916fa0 fs/fat:  Clean up some name BS_ and MBR_ refer to the same record and should use the same naming (MBR_).
f0b4f14 Eliminate some new warnings reported in build testing.
3cc79be examples/lvgldemo/ and graphics/littlevgl/:  pdate LVGL to version 5.1.1
1030ea7 Merged in masayuki2009/nuttx.apps/fix_mksymtab (pull request #147)
cb9e951 apps/Make.defs:  Improve the symtab target.  tools/mksymtab.sh:  Fix a typo.
296f583 apps/tools:  Forgot to include a file with last commit.