misc: Get rid of constants used for critical path annotation.
misc: Get rid of constants used for critical path annotation.

The constant for the critical path annotation function itself is still
used in gem5 along with the M5OP_RESERVED opcodes to signal
unimplemented functions.

Change-Id: I71c7a56d0346f8aafe23e733a1eea703dda1af92
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27222
Reviewed-by: Jason Lowe-Power <92de577f37050ad05b60626d2f17913f40dcb1a2@gmail.com>
Maintainer: Jason Lowe-Power <92de577f37050ad05b60626d2f17913f40dcb1a2@gmail.com>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>

gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5