[dv/chip] Add chip_sw_otp_prim_tl_access to chip testplan
[dv/chip] Add chip_sw_otp_prim_tl_access to chip testplan

This PR:
1). Add a testplan entry for chip_sw_otp_prim_tl_access.
2). Slightly modify the description of the
  `chip_sw_flash_prim_tl_acess`.

Signed-off-by: Cindy Chen <399ad771a111eac8923348b1e2af093034e5d4f1@opentitan.org>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan