provision: invalid certificate when read back if set option "--creds_address"

[wilbur-se]

As flash overlap for provision data and mfg token (enable signing and encryption) for efr32mg24 (both using last page by default), so update the end for flash to 0x0817c000 from 0x0817E000 for application and bootloader.
So then running provisioin script, set option --creds_address to 0x0817E000. Provision is fine, but read dac_cert and pai_cert by provision script, the returned valid is invalid certificate. If using default creds_address, no this issue