cpu/x86/sipi: Add x86_64 support

Enter long mode on secondary APs.

Tested on Lenovo T410 with additional x86_64 patches.
Tested on HP Z220 with additional x86_64 patches.

Still boots on x86_32.

Change-Id: I53eae082123d1a12cfa97ead1d87d84db4a334c0
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45187
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

0 files changed, 0 insertions, 0 deletions