security/tpm2-abrmd: Improve rc.d script and add devd config

• Improve tpm2-abrmd rc.d script
• Add devd config file, which adds rules for /dev/tpm0 char device. It allows the _tss group members to read and write the tpm device, which is required by tpm2-abrmd to communicate with the device.

Differential Revision: https://reviews.freebsd.org/D34744