Modularize CMSIS-DSP and add full examples

[salkinium]

This modularizes CMSIS-DSP to reduce the amount of source files that need to be compiled for your project and fixes #239.

This also wraps all CMSIS-DSP examples into modm examples to check for regressions in future.

cc @se-bi @chris-durand

[salkinium]

This is epic… ARM thought it would be a fantastic idea to declare arm_linear_interep_table not as const, so it gets placed into SRAM, which at 736kB does not fit (surprise, surprise).
I can fix that with this define, however, the arm_linear_interp_instance_f32 structure requires a non-const float*
pointer, so there is a cast missing, which normally causes a compile error. But with -fpermissive I can reduce this to a warning:

In file included from main.cpp:25:
../../../../ext/arm/cmsis/CMSIS/DSP/Examples/ARM/arm_linear_interp_example/arm_linear_interp_example_f32.c: In function 'int32_t arm_cmsis_dsp_example()':
../../../../ext/arm/cmsis/CMSIS/DSP/Examples/ARM/arm_linear_interp_example/arm_linear_interp_example_f32.c:151:80: warning: invalid conversion from 'const float*' to 'float32_t*' {aka 'float*'} [-fpermissive]
   arm_linear_interp_instance_f32 S = {188495, -3.141592653589793238, XSPACING, &arm_linear_interep_table[0]};
                                                                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

This is the best I can do…

[salkinium]

So to summarize… All these examples run in a int32_t main() function and write their success to a arm_status status variable and always end with while(1); and it's the only use of the while keyword in that file…

Hmmmmmmm 🤔🤔🤔🤔 what if we just redefine a few things…

😳 #define while return status; void 👀