manifest: mcuboot 1.5.0 revision

Introduce exact 1.5.0 mcuboot release version
Difference to previous reference:
- imgtool: fix passing --erased-val with 0xff value
- mcuboot internal sim patches (not affected zephyr)
- release note ect.
- introduced default recovery trigger pin configuration for nRF5340

** No mcuboot embedded C code changes at all. **

Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>