powerpc/mm: Fix section mismatch warning

stable inclusion
from linux-4.19.100
commit 58ddf0b0eff2a6cb536082fc6b046f5eb51c240c

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

commit 26ad2671 upstream.

This patch fix the below section mismatch warnings.

WARNING: vmlinux.o(.text+0x2d1f44): Section mismatch in reference from the function devm_memremap_pages_release() to the function .meminit.text:arch_remove_memory()
WARNING: vmlinux.o(.text+0x2d265c): Section mismatch in reference from the function devm_memremap_pages() to the function .meminit.text:arch_add_memory()
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/powerpc/mm/mem.c

@@ -118,8 +118,8 @@ int __weak remove_section_mapping(unsigned long start, unsigned long end)
 	return -ENODEV;
 }
 
-int __meminit arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
-		bool want_memblock)
+int __ref arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
+			  bool want_memblock)
 {
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;
@@ -140,8 +140,8 @@ int __meminit arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *
 }
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
-int __meminit arch_remove_memory(int nid, u64 start, u64 size,
-					struct vmem_altmap *altmap)
+int __ref arch_remove_memory(int nid, u64 start, u64 size,
+			     struct vmem_altmap *altmap)
 {
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;