riscv: Fixup CONFIG_GENERIC_TIME_VSYSCALL

The patch fix commit: ad5d1122 ("riscv: use vDSO common flow to
reduce the latency of the time-related functions").

The GENERIC_TIME_VSYSCALL should be CONFIG_GENERIC_TIME_VSYSCALL
or vgettimeofday won't work.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Fixes: ad5d1122 ("riscv: use vDSO common flow to reduce the latency of the time-related functions")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

arch/riscv/include/asm/vdso.h

@@ -10,7 +10,7 @@
 
 #include <linux/types.h>
 
-#ifndef GENERIC_TIME_VSYSCALL
+#ifndef CONFIG_GENERIC_TIME_VSYSCALL
 struct vdso_data {
 };
 #endif

arch/riscv/kernel/vdso.c

@@ -12,7 +12,7 @@
 #include <linux/binfmts.h>
 #include <linux/err.h>
 #include <asm/page.h>
-#ifdef GENERIC_TIME_VSYSCALL
+#ifdef CONFIG_GENERIC_TIME_VSYSCALL
 #include <vdso/datapage.h>
 #else
 #include <asm/vdso.h>