unified: Eliminate k_stack_init_with_buffer()

Folds this API into k_stack_init() to provide a single API
that requires the caller to pass in the stack buffer, just
as is done for other kernel objects initialization APIs
involving the use of a buffer.

Change-Id: Icad5fd6e5387d634738d1574f8dfbc5421cd642d
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
3 files changed