aboot: mdtp: Fix MDTP eFuse read

LK cannot use SCM to read eFuses anymore, since this call
is blocked to LK from security reasons. Though, MDTP eFuse
is allowed to be accessed directly from HLOS.
This commit modifies MDTP eFuse read logic, such that it
is read directly via IO READ. The MDTP eFuse address is fixed
as well.

Change-Id: I15d04cd6bbf454422adbcfe9466774546c291d8d
2 files changed