configure: Add --image-base check for non-i386

configure: Add --image-base check for non-i386

Configure check grub_PROG_OBJCOPY_ABSOLUTE is run for all non-Apple
targets. With ld.lld-21, the check fails for addresses below image base
address (which ld.lld-21 assumes is 0x200000).

Fix by checking if linker support --image-base flag, and if it does,
include "--image-base 0" to TARGET_IMG_BASE_LDOPT.

The AX_CHECK_LINK_FLAG macro has been added to avoid a dependency on
autoconf-archive.

Note: I tried this approach with i386-pc, but I ended up with a GRUB
image that failed to boot correctly.

Signed-off-by: Nicholas Vinson <nvinson234@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>