sgx-detect: interactive debug

[shreevari]

I plan to work on enabling SGX via software with sgx-detect interactively. It requires that I update the EPCSW EFI variable, hence this change.

I also need some help with the default attributes for the EFI variables.

[shreevari]

I'm having issues writing EFI varibles to the environment. There's an OS error (Error number 5 - EIO).
This thread suggests that I remove the immutable attribute and write out the file, but I'm still getting the same error.
I am unable to set e attribute on the file through command line too.

Any help is welcome