[build] include alignment into section size calculations

[avtolstoy]

Problem

Some applications that use non-trivial alignments (32, 128 etc) may fail to build with SRAM or other section overflow.

#2665 is somewhat relevant.

Solution

Account for section alignment requirements when calculating its size. Objdump provides this:

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
  3 .dynalib      00000008  023e0b88  085e00b0  00010b88  2**3

The calculation is a bit trivial but should work for what we are doing: size + algn - 1

Steps to Test

• wiring/no_fixture with MISC_02_alignment should build on all platforms

Example App

This should build:

__attribute__((used, aligned(256))) uint8_t test[63] = {};

/* executes once at startup */
void setup() {
    // To avoid compiler optimizing 'test' out
    LOG(INFO, "%d", (int)test[0]);
}

References

Links to the Community, Docs, Other Issues, etc..

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Completeness

• User is totes amazing for contributing!
• Contributor has signed CLA (Info here)
• Problem and Solution clearly stated
• Run unit/integration/application tests on device
• Added documentation
• Added to CHANGELOG.md after merging (add links to docs and issues)