drm/xe: Do not include current dir for generated/xe_wa_oob.h

The generated file 'generated/xe_wa_oob.h' is included using:
"generated/xe_wa_oob.h"
which first look inside the source code. But the file resides
in the build directory and should therefore be included using:
<generated/xe_wa_oob.h>

Signed-off-by: Dafna Hirschfeld <dhirschfeld@habana.ai>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240221083622.1584492-1-dhirschfeld@habana.ai