ruby: Use arm32 for coroutines on 32bit-arm

in 2.7 [2] ruby enabled ucontext for coroutines on arm32 but it does not
work for musl since it uses glibc specific functions e.g.
getcontext/swapcontext/swapcontext also see [1]

This patch reverts back to using arm32 implementation for coroutines on
arm

[1] https://bugs.ruby-lang.org/issues/16455#change-83442
[2] 6c6bf9ffcb (diff-7fccec8474e2184cd2518046bf39d54cL10)

(From OE-Core rev: ea93afa4c1c40d74faf321baa78a29d0ad7d3223)

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/ruby/ruby_2.7.0.bb

@@ -25,6 +25,9 @@ EXTRA_OECONF = "\
     --with-pkg-config=pkg-config \
 "
 
+EXTRA_OECONF_append_libc-musl_arm = " --with-coroutine=arm32"
+EXTRA_OECONF_append_libc-musl_armeb = " --with-coroutine=arm32"
+
 do_install() {
     oe_runmake 'DESTDIR=${D}' install
 }