add musl 1.2.0 and make it default

Makefile

@@ -4,7 +4,7 @@ SOURCES = sources
 CONFIG_SUB_REV = 3d5db9ebe860
 BINUTILS_VER = 2.33.1
 GCC_VER = 9.2.0
-MUSL_VER = 1.1.24
+MUSL_VER = 1.2.0
 GMP_VER = 6.1.2
 MPC_VER = 1.1.0
 MPFR_VER = 4.0.2

hashes/musl-1.2.0.tar.gz.sha1

@@ -0,0 +1 @@
+140038a5376ca3a4e69168ed6c3879d1477b20d1  musl-1.2.0.tar.gz