arch: arm: Separate common swap code
There are too many differences between Cortex-A/R and Cortex-M on swap
code. For reducing the complexity and easier to maintain, this commit
introduces the following major changes
1. Separate swap.c and swap_helper.S into two different parts based on
the architecture.
2. Rename 'z_arm_pendsv' to 'z_arm_do_swap' for Cortex-A/R.
3. Removes the part related to the option 'CONFIG_BUILTIN_STACK_GUARD'
in 'cortex_a_r/swap_helper.S' because this code is written for
the Cortex-M architecture.
Signed-off-by: Huifeng Zhang <Huifeng.Zhang@arm.com>
8 files changed
