Merge: redhat/configs: Disable CONFIG_EFI_MIXED in RHEL

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-10/-/merge_requests/1512

JIRA: https://issues.redhat.com/browse/RHEL-115521

Upstream Status: git@gitlab.com:cki-project/kernel-ark.git

commit bbfe516bba796cbca8702877f77350482fccc72c
Author: Lenny Szubowicz <lszubowi@redhat.com>
Date:   Mon Sep 22 20:50:57 2025 -0400

    redhat/configs: Disable CONFIG_EFI_MIXED in RHEL

    Disable CONFIG_EFI_MIXED in RHEL but keep it enabled in Fedora.

    CONFIG_EFI_MIXED is an X86_64-only parameter that enables support
    in the kernel for booting and running a 64-bit kernel on an X86 system
    that has 32-bit EFI firmware even though the processor is 64-bit capable.

    Such systems have never been supported by RHEL. CONFIG_EFI_MIXED adds some
    code and complexity to the EFI stub. It also adds some marginal overhead
    to EFI runtime calls. Therefore, remove it from RHEL.

    Signed-off-by: Lenny Szubowicz <lszubowi@redhat.com>

Signed-off-by: Lenny Szubowicz <lszubowi@redhat.com>

Approved-by: David Arcari <darcari@redhat.com>
Approved-by: Daniel Horak <dhorak@redhat.com>
Approved-by: Charles Mirabile <cmirabil@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: CKI GitLab Kmaint Pipeline Bot <26919896-cki-kmaint-pipeline-bot@users.noreply.gitlab.com>

Author: CKI KWF Bot

redhat/configs/common/generic/x86/CONFIG_EFI_MIXED

@@ -0,0 +1 @@
+# CONFIG_EFI_MIXED is not set