Support build on Linux target (DSP-159)

[howard0su]

1. Avoid include esp_cpu on Linux target
2. Fix warnings regarding size_t v.s. int on Log

Description

Build support on Linux target.

Fix #85

Testing

Verified via test_app.
All cases passed except

1. matrix reverse test failed due to a slight large calculation error (0.000145 > 1e-4).

Error at[3] = 0.000145, expected= -38.000000, calculated = -38.000145
/home/howardsu/esp-dsp/modules/matrix/mul/test/test_mat_sub_f32.cpp:826:Matrix subset methods check:FAIL:Function [dspm].  Error in inverse() operation!\n

2. Time Error in 10 cases, which I believe it is due to the difference of cycle tracking. On Linux, I uses rdtsc.

Error at[3] = 0.000145, expected= -38.000000, calculated = -38.000145
/home/howardsu/esp-dsp/modules/matrix/mul/test/test_mat_sub_f32.cpp:826:Matrix subset methods check:FAIL:Function [dspm].  Error in inverse() operation!\n

Checklist

Before submitting a Pull Request, please ensure the following:

• 🚨 This PR does not introduce breaking changes.
• All CI checks (GH Actions) pass.
• Documentation is updated as needed.
• Tests are updated or added as necessary.
• Code is well-commented, especially in complex areas.
• Git history is clean — commits are squashed to the minimum necessary.

[dmitry1945]

Hi @howard0su
I will add this into the master this week.

Thank you very much!

[howard0su]

Thanks. Please note, This change only supports Linux target of x86/x86_64 because I am using rdtsc to get the CPU cycles.

[dmitry1945]

@howard0su
I have taken the commit from your fork. I think we can close this MR.
Are you agree?

[howard0su]

yes, please

[morgana2313]

Thanks. Please note, This change only supports Linux target of x86/x86_64 because I am using rdtsc to get the CPU cycles.

So this commit won't work on Mac with Apple silicon (AArch64)?

[howard0su]

No. it needs additional changes to OSX as it miss some APIs like align_malloc.