Selecting CONFIG_DEBUG_INFO_BTF results in the below warning from ld:
  ld: warning: orphan section `.BTF' from `.btf.vmlinux.bin.o' being placed in section `.BTF'
Include .BTF section in vmlinux explicitly to fix the same.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200220113132.857132-1-naveen.n.rao@linux.vnet.ibm.com
                *(.branch_lt)
        }
 
+#ifdef CONFIG_DEBUG_INFO_BTF
+       .BTF : AT(ADDR(.BTF) - LOAD_OFFSET) {
+               *(.BTF)
+       }
+#endif
+
        .opd : AT(ADDR(.opd) - LOAD_OFFSET) {
                __start_opd = .;
                KEEP(*(.opd))