SPM: Remame the thread function 'thrd_wait_on()'

The thread function 'thrd_wait_on()' actually sets the thread
state to blocked, the name is confusing and may indicate inside
the function CPU is blocked and waits for some signals.

This patch changes the function name to 'thrd_set_wait()'.

Signed-off-by: Mingyang Sun <mingyang.sun@arm.com>
Change-Id: Iad29e2db89f8e5ccb34022506afb3f8c7d188d6b
3 files changed