Change MINSIGSTKSZ and SIGSTKSIZE

[Haren Myneni]

Alan, 
	LTP test (signalstack02) is failing. This test expects -ENOMEM from
kernel when passing less than stack size (passing 4095). MINSIGSTKSZ in
signal.h (glibc) is changed to 4096 to support VSX changes
(https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=f7c399cff5bd04ee9dc117fb6b0f39597dc047c6)  We should also change these values in kernel to match with glibc. Any issues? 

diff --git a/arch/powerpc/include/uapi/asm/signal.h
b/arch/powerpc/include/uapi/
index 6c69ee9..18f498e 100644
--- a/arch/powerpc/include/uapi/asm/signal.h
+++ b/arch/powerpc/include/uapi/asm/signal.h
@@ -85,8 +85,8 @@ typedef struct {
 
 #define SA_RESTORER    0x04000000U
 
-#define MINSIGSTKSZ    2048
-#define SIGSTKSZ       8192
+#define MINSIGSTKSZ    4096
+#define SIGSTKSZ       16384

Thanks
Haren