Remove unused includes in aarch64-linux-tdep.c

Remove unused includes in aarch64-linux-tdep.c

include-what-you-use reports:

../../../src/binutils-gdb/gdb/aarch64-linux-tdep.c should remove these lines:
- #include "arch-utils.h"  // lines 24-24
- #include "auxv.h"  // lines 48-48
- #include "cli/cli-utils.h"  // lines 39-39
- #include "elf/common.h"  // lines 49-49
- #include "inferior.h"  // lines 35-35

Add an include for "target/target.h", otherwise target_read_memory isn't
found.

gdb/ChangeLog:

	* aarch64-linux-tdep.c: Remove includes.