boards/stm32f469i-disco: enable FMC with SDRAM support

[gschorcht]

Contribution description

This PR enables the FMC support on the stm32f469i-disco board and the on-board SDRAM ISSI IS42S32400F-6BL with 16 MByte.

Testing procedure

1. tests/periph/fmc should succeed, just compile and flash the app with

   BOARD=stm32f469i-disco make -C tests/periph/fmc flash term
   

2. tests/sys/malloc should also use the SDRAM. Use

   USEMODULE=periph_fmc_sdram CFLAGS='-DCHUNK_SIZE=131072' \
   BOARD=stm32f469i-disco make -C tests/sys/malloc flash term
   

   and check that the heap also uses the memory in the range from 0xc0000000 to 0xc0fffffff.

Issues/PRs references

[riot-ci]

Murdock results

✔️ PASSED

5f97873 boards/stm32f469i-disco: add FMC with SDRAM support

Success	Failures	Total	Runtime
535	0	535	03m:27s

Artifacts

• Documentation preview

[aabadie]

bors merge

[bors]

Build succeeded!

The publicly hosted instance of bors-ng is deprecated and will go away soon.

If you want to self-host your own instance, instructions are here.
For more help, visit the forum.

If you want to switch to GitHub's built-in merge queue, visit their help page.

• Murdock
• static-tests
• tools-build-success