startup: make sdlog2 working again on FMUv1
position_estimator_inav: lower RAM
Revert "position_estimator_inav: lower RAM"

This reverts commit b457e714972649f5a39fa3f2f9463bdfe6971fcc.
Merge pull request #633 from PX4/fmuv1_ram_cleanup

Fmuv1 ram cleanup