convert license headers to SPDX

Includes license review of 3rd-party files, adding missing upstream
headers, and moving the UNSW OZPLB license into its own file rather
than replicating it in the header.

elfloader-tool: explicitly link config libs

explicitly link kernel_autoconf and elfloader_Config
since the global config lib is going to be remove

elfloader: Add aarch32 EFI support

This makes the ELF loader relocatable on aarch32,
and generates the appropriate EFI header for aarch32 boards.

Disable Async aborts that might be pending from bootloader and enable SMP bit

SELFOUR-743: SMP - Disable dcaches to maintain coherency during synchronization

Currently the elfoader relies on u-boot's MMU/Caches configurations. u-boot can
introduce unexpected behaviors for each platform when it comes to caches/coherency
between cores:

u-boot can configure CPUn's MMU/caches to be unshareable, and does not set SMP bit,
in which case our elfloader would simply get stuck reading the wrong non_boot_lock
value from CPUn's L1-cache.

D-cache needs to be disabled/cleaned per-CPU, and SMP bit to be enabled in order for the
non_boot_lock synchronization to work properly regardless of how u-boot configures
MMU/Caches/CPUs.

Fix whitespace

- remove trailing whitespace
- remove duplicate blank lines
- remove blank lines at end of file

Fix licenses

SMP: s/CONFIG_SMP_ARM_MPCORE/CONFIG_MAX_NUM_NODES

elfloader: Stop using SEL4_ARCH for selective compilation in Makefile