x86/resctrl: Annotate get_mem_config() functions as __init

After a recent LLVM change [1] that deduces __cold on functions that only call
cold code (such as __init functions), there is a section mismatch warning from
__get_mem_config_intel(), which got moved to .text.unlikely. as a result of
that optimization:

  WARNING: modpost: vmlinux: section mismatch in reference: \
  __get_mem_config_intel+0x77 (section: .text.unlikely.) -> thread_throttle_mode_init (section: .init.text)

Mark __get_mem_config_intel() as __init as well since it is only called
from __init code, which clears up the warning.

While __rdt_get_mem_config_amd() does not exhibit a warning because it
does not call any __init code, it is a similar function that is only
called from __init code like __get_mem_config_intel(), so mark it __init
as well to keep the code symmetrical.

CONFIG_SECTION_MISMATCH_WARN_ONLY=n would turn this into a fatal error.

Fixes: 05b93417 ("x86/intel_rdt/mba: Add primary support for Memory Bandwidth Allocation (MBA)")
Fixes: 4d05bf71 ("x86/resctrl: Introduce AMD QOS feature")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: <stable@kernel.org>
Link: https://github.com/llvm/llvm-project/commit/6b11573b8c5e3d36beee099dbe7347c2a007bf53 [1]
Link: https://lore.kernel.org/r/20240917-x86-restctrl-get_mem_config_intel-init-v3-1-10d521256284@kernel.org

arch/x86/kernel/cpu/resctrl/core.c

@@ -207,7 +207,7 @@ static inline bool rdt_get_mb_table(struct rdt_resource *r)
 	return false;
 }
 
-static bool __get_mem_config_intel(struct rdt_resource *r)
+static __init bool __get_mem_config_intel(struct rdt_resource *r)
 {
 	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
 	union cpuid_0x10_3_eax eax;
@@ -241,7 +241,7 @@ static bool __get_mem_config_intel(struct rdt_resource *r)
 	return true;
 }
 
-static bool __rdt_get_mem_config_amd(struct rdt_resource *r)
+static __init bool __rdt_get_mem_config_amd(struct rdt_resource *r)
 {
 	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
 	u32 eax, ebx, ecx, edx, subleaf;