arm64: fix ftrace due to bad cherry-picks from mainline v3.19

Three patches were cherry-picked incorrectly from mainline to android-3.18:

c852f320 arm64: Emulate CP15 Barrier instructions
bd35a4ad arm64: Port SWP/SWPB emulation support from arm
9b79f52d arm64: Add support for hooks to handle undefined instructions

In all cases, the added hunks should have been above
"#endif /*__ASSEMBLY */" in arch/arm64/include/asm/insn.h.

The bad merge breaks ftrace compilation on arm64 (e.g. with the following
lines added to arch/arm64/configs/defconfig):
 CONFIG_FTRACE=y
 CONFIG_FUNCTION_TRACER=y

Here is the breakage:
  AS      arch/arm64/kernel/entry-ftrace.o
./arch/arm64/include/asm/insn.h: Assembler messages:
./arch/arm64/include/asm/insn.h:359: Error: unknown mnemonic `bool' -- `bool aarch32_insn_is_wide(u32 insn)'
./arch/arm64/include/asm/insn.h:365: Error: unknown mnemonic `u32' -- `u32 aarch32_insn_extract_reg_num(u32 insn,int offset)'
./arch/arm64/include/asm/insn.h:366: Error: unknown mnemonic `u32' -- `u32 aarch32_insn_mcr_extract_opc2(u32 insn)'
./arch/arm64/include/asm/insn.h:367: Error: unknown mnemonic `u32' -- `u32 aarch32_insn_mcr_extract_crm(u32 insn)'
scripts/Makefile.build:293: recipe for target 'arch/arm64/kernel/entry-ftrace.o' failed

Signed-off-by: Daniel Kurtz <djkurtz@google.com>
Change-Id: I87e83afcad8665e52f9e6ed7dac856f45670e3e6