x86/include/arch/cpuid.h: Fix inline assembly

In the cpuid helper functions eax is always written to
by the cpuid instruction, so add it to the output clobbered list.

This prevents GCC from generating code with undefined behaviour
when the function is inlined.

Test: Verified that the generated assembly is sane and runtime
      tests showed no "strange" behaviour when calling cpuid
      functions.

Change-Id: I5dc0bb620184a355716b9c8d4206d55554b41ab9
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78192
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Krystian Hebel <krystian.hebel@3mdeb.com>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>

0 files changed, 0 insertions, 0 deletions