libpayload: Add VBOOT_X86_RSA_ACCELERATION config

Add `VBOOT_X86_RSA_ACCELERATION' Kconfig option to enable SSE2
instruction set implementation of modulus exponentiation which is part
of the RSA signature verification process. This option is enabled on
CHROMEOS.

| modpow() function call | original on rex0 | SSE2 on rex0 |
|------------------------+------------------+--------------|
| depthcharge - step 1   |            0.547 |        0.288 |
| depthcharge - step 2   |            0.152 |        0.081 |
| depthcharge - step 3   |            0.164 |        0.079 |
|------------------------+------------------+--------------|
| Total (ms)             |            0.863 |        0.448 |

| modpow() function call | original on brya0 | SSE2 on rex0 |
|------------------------+-------------------+--------------|
| depthcharge - step 1   |             0.693 |        0.248 |
| depthcharge - step 2   |             0.172 |        0.065 |
| depthcharge - step 3   |             0.223 |        0.067 |
|------------------------+-------------------+--------------|
| Total (ms)             |             1.088 |         0.38 |

BUG=b:312709384
TEST=modular exponentiation is about twice faster on rex0 and brya0

Change-Id: I801ebd7839261c6bd07fb218e1e36a7108e219bf
Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/79290
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>

0 files changed, 0 insertions, 0 deletions