Fix following issues:
WARNING: vmlinux.o(.text+0x3aba): Section mismatch in reference from the function xen_align_and_add_e820_region() to the function .init.text:e820_add_region()
The function xen_align_and_add_e820_region() references
the function __init e820_add_region().
This is often because xen_align_and_add_e820_region lacks a __init
annotation or the annotation of e820_add_region is wrong.
WARNING: vmlinux.o(.text+0x2e9ec): Section mismatch in reference from the function acpi_map_cpu2node() to the variable .cpuinit.data:__apicid_to_node
The function acpi_map_cpu2node() references
the variable __cpuinitdata __apicid_to_node.
This is often because acpi_map_cpu2node lacks a __cpuinitdata
annotation or the annotation of __apicid_to_node is wrong.
WARNING: vmlinux.o(.text+0x2e9f1): Section mismatch in reference from the function acpi_map_cpu2node() to the function .cpuinit.text:numa_set_node()
The function acpi_map_cpu2node() references
the function __cpuinit numa_set_node().
This is often because acpi_map_cpu2node lacks a __cpuinit
annotation or the annotation of numa_set_node is wrong.
WARNING: vmlinux.o(.text+0x3f9b4): Section mismatch in reference from the function enable_iommus() to the function .init.text:iommu_set_device_table()
The function enable_iommus() references
the function __init iommu_set_device_table().
This is often because enable_iommus lacks a __init
annotation or the annotation of iommu_set_device_table is wrong.