openssl: Pass in any TARGET_ASFLAGS

Packages not picking up the regular TARGET_AS need their openwrt
Makefiles tweaked. For a basic build, that's just openssl.

This depends on patch 1/5.

Signed-off-by: Jay Carlson <nop@nop.com>
Signed-off-by: Florian Fainelli <florian@openwrt.org>

SVN-Revision: 36201