LoongArch: vdso: Use generic union vdso_data_store

There is already a generic union definition for vdso_data_store in vdso
datapage header.

Use this definition to prevent code duplication.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240219153939.75719-9-anna-maria@linutronix.de

arch/loongarch/kernel/vdso.c

@@ -21,15 +21,13 @@
 #include <asm/vdso.h>
 #include <vdso/helpers.h>
 #include <vdso/vsyscall.h>
+#include <vdso/datapage.h>
 #include <generated/vdso-offsets.h>
 
 extern char vdso_start[], vdso_end[];
 
 /* Kernel-provided data used by the VDSO. */
-static union {
-	u8 page[PAGE_SIZE];
-	struct vdso_data data[CS_BASES];
-} generic_vdso_data __page_aligned_data;
+static union vdso_data_store generic_vdso_data __page_aligned_data;
 
 static union {
 	u8 page[LOONGARCH_VDSO_DATA_SIZE];