or1k: Add missing changelog entries.

Those should have been coupled with respective commits,
but due to certain circumstances, that didn't happen.
Use -muclibc / -mglibc to detect wanted interp to -dynamic_linker
Use -fno-dwarf2-cfi-asm on CRTSTUFF to leave eh_frame empty.
Do not assume uclibc when -m glibc is absent, use target configuration instead.
Use GNU userspace link options when compiling for Linux.