build: silence GNU ld 2.39 warning about executable stacks

build: silence GNU ld 2.39 warning about executable stacks

While for C files the compiler is supposed to arrange for emitting
respective information, for assembly sources we're responsible ourselves.

For the new use of cc-option to work we cannot pass -S to the compiler
anymore. We need the compiler to actually invoke the assembler, so switch
to using -c.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>