xtensa: remove arch/xtensa/include/asm/types.h

Xtensa does not define CONFIG_64BIT. The generic definition of
BITS_PER_LONG in include/asm-generic/bitsperlong.h should work.
With that definition removed from arch/xtensa/include/asm/types.h
it does nothing but including arch/xtensa/include/uapi/asm/types.h
Remove the arch/xtensa/include/asm/types.h header.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>