[ARM] 4496/1: elf_hwcap: fix up #include misplacement

While bisecting an iop13xx compile failure I noticed that
include/asm-arm/hwcap.h should be included from include/asm-arm/elf.h
outside #ifndef __ASSEMBLY__ since hwcap.h has its own __ASSEMBLY__
protections.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>