Fixed building without linux/input.h

https://github.com/libsdl-org/SDL/issues/6169

CMakeLists.txt

@@ -1010,6 +1010,7 @@ if(SDL_LIBC)
       string(REPLACE "." "_" _HAVE_H ${_UPPER})
       check_include_file("${_HEADER}" ${_HAVE_H})
     endforeach()
+    check_include_file(linux/input.h HAVE_LINUX_INPUT_H)
 
     set(STDC_HEADER_NAMES "stddef.h;stdarg.h;stdlib.h;string.h;stdio.h;wchar.h;float.h")
     check_include_files("${STDC_HEADER_NAMES}" STDC_HEADERS)
@@ -1579,7 +1580,7 @@ elseif(UNIX AND NOT APPLE AND NOT RISCOS AND NOT HAIKU)
     if(FREEBSD OR NETBSD OR OPENBSD OR BSDI)
       CheckUSBHID()
     endif()
-    if(LINUX AND NOT ANDROID)
+    if(LINUX AND HAVE_LINUX_INPUT_H AND NOT ANDROID)
       set(SDL_JOYSTICK_LINUX 1)
       file(GLOB JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/linux/*.c ${SDL2_SOURCE_DIR}/src/joystick/steam/*.c)
       list(APPEND SOURCE_FILES ${JOYSTICK_SOURCES})