Unify cache flush code path after image load

Previously the cache flush happened in 2 different places in code
depending on whether TRUSTED_BOARD_BOOT is enabled or not. This
patch unifies this code path for both the cases. The `load_image()`
function is now made an internal static function.

Change-Id: I96a1da29d29236bbc34b1c95053e6a9a7fc98a54
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
2 files changed