musl: s390x: Fix definition of SIGSTKSZ/MINSIGSTKSZ

These have had the values 10240 and 4096 respectively since the introduction
of the s390x port in musl back in 2016.

Signed-off-by: Jens Reidel <adrian@travitia.xyz>

Author: Gelbpunkt

src/unix/linux_like/linux/musl/b64/s390x.rs

@@ -161,8 +161,8 @@ pub const SA_NOCLDWAIT: c_int = 2;
 pub const SA_ONSTACK: c_int = 0x08000000;
 pub const SA_SIGINFO: c_int = 4;
 pub const SIGBUS: c_int = 7;
-pub const SIGSTKSZ: size_t = 0x2000;
-pub const MINSIGSTKSZ: size_t = 2048;
+pub const SIGSTKSZ: size_t = 10240;
+pub const MINSIGSTKSZ: size_t = 4096;
 pub const SIG_SETMASK: c_int = 2;
 
 pub const O_NOCTTY: c_int = 256;