patch 9.0.0588: MorphOS build is broken

Problem:    MorphOS build is broken.
Solution:   Add "-lm" to LDFLAGS and "-noixemul" to CFLAGS. (Ola Söder,
            closes #11222)
diff --git a/src/Make_ami.mak b/src/Make_ami.mak
index dd674dc..77ec32c 100644
--- a/src/Make_ami.mak
+++ b/src/Make_ami.mak
@@ -68,7 +68,8 @@
 LDFLAGS = -DHAVE_FSYNC -ldebug
 else
 ifeq ($(UNM),MorphOS)
-LDFLAGS = -ldebug -noixemul
+CFLAGS += -noixemul
+LDFLAGS = -ldebug -lm -noixemul
 endif
 endif
 endif