SDL: Fixed building on older kernel headers

SDL Commits
1 
From b98494a10154d4e6944279125a2194cac20d7c85 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Sat, 17 Jun 2023 09:39:50 -0700
Subject: [PATCH] Fixed building on older kernel headers

---
 src/core/linux/SDL_evdev_capabilities.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/core/linux/SDL_evdev_capabilities.h b/src/core/linux/SDL_evdev_capabilities.h
index 91364df6a8ff..df9537a57d65 100644
--- a/src/core/linux/SDL_evdev_capabilities.h
+++ b/src/core/linux/SDL_evdev_capabilities.h
@@ -28,6 +28,9 @@
 
 #include <linux/input.h>
 
+#ifndef INPUT_PROP_ACCELEROMETER
+#define INPUT_PROP_ACCELEROMETER 0x06
+#endif
 #ifndef INPUT_PROP_MAX
 #define INPUT_PROP_MAX 0x1f
 #endif