fix(x86_64/linker.ld): put boot/GDT in a page-aligned ELF section
fix(x86_64/linker.ld): put boot/GDT in a page-aligned ELF section

This may not be the Right Way to do this, but it works for now &
prevents crashes.

rachlmac/sos-kernel,rachlmac/sos-kernel,hawkw/sos-kernel,hawkw/sos-kernel,rachlmac/sos-kernel,hawkw/sos-kernel