refactor(twed): improve TWED enablement in EL-3

The current implementation uses plat_arm API under generic code.
"plat_arm" API is a convention used with Arm common platform layer
and is reserved for that purpose. In addition, the function has a
weak definition which is not encouraged in TF-A.

Henceforth, removing the weak API with a configurable macro "TWED_DELAY"
of numeric data type in generic code and simplifying the implementation.
By default "TWED_DELAY" is defined to zero, and the delay value need to
be explicitly set by the platforms during buildtime.

Signed-off-by: Jayanth Dodderi Chidanand <>
Change-Id: I25cd6f628e863dc40415ced3a82d0662fdf2d75a
8 files changed