livepatch/core: Add support for arm for klp relocation

hulk inclusion
category: feature
bugzilla: 51923
CVE: NA

---------------------------

In the older version of livepatch implementation without ftrace on
arm, it use klp_relocs and do special relocation for klp syms. The
kpatch-build front-tools use kpatch version to generate klp_relocs.

After commit 7c8e2bdd ("livepatch: Apply vmlinux-specific KLP
relocations early") and commit 425595a7 ("livepatch: reuse module
loader code to write relocations"), the mainline klp relocation flow
is always using ".klp.rela." section and kpatch-build front-tools use
klp version to generate klp module.

The default klp_apply_section_relocs is only for 64bit and modules
with rela support. Because CONFIG_MODULES_USE_ELF_REL is set in arm,
so we modify klp relocation to support 32bit and modules using rel.
Also the kpatch-build front-tools should adapter to support this.

Signed-off-by: Dong Kai <dongkai11@huawei.com>

Signed-off-by: Ye Weihua <yeweihua4@huawei.com>
Reviewed-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>