[musl][bootloader] Use compiler-provided standard headers

<stdalign.h>, <stdarg.h>, <stdbool.h>, <stddef.h>, <stdint.h>
are all provided by the compiler and should not be replaced here.

The bootloader code's local versions were sloppy in what names
got defined where, so the code needed some #include additions
and type adjustments.

TC-32 #done

Change-Id: Ib24ba7b5072e99ec9302a6994d63ad5e16233151

[musl] Clang format musl

Change-Id: I36438df9b3065229e365b70a4b9219de869e3acd

[musl] Fix userspace int types and format specifiers

This also fixes two bugs in the kernel libc equivalents.

In addition, remove a number of unneeded inclusions of <sys/types.h>
throughout system, and fix some format specifiers. Also add a test of
these things (which found the bugs mentioned above).

Change-Id: I4051394276340b00673510494eb9b8942dc55561

[musl] Use #pragma once in musl's public headers

Like the prior commit, this only replaces existing ifdef guards.

Change-Id: I39be129111db9f129aef72a53f986ce6a49376ac

[musl] update the PRI* macros to match the underlying integer types for *int*_t

Change-Id: Ic373c4de514ef5fda20e7b196f75a3d7379443a9

[magenta] Initial commit