oem-ibm: Adding value_name json key for dynamic deallocation of Memory

This commit adds value_name json key to BIOS attribute that allows user
to enable/disable the dynamic deallocation of memory based on predictive
memory fail events.

Tested: Verified the BIOS attribute with get bios attribute command from
pldmtool.

Change-Id: I913d2062c1d7af024a447f9eb4e0289fa7ebdf12
Signed-off-by: Riya Dixit <riyadixitagra@gmail.com>