linux-phytec-ti

drm/tidss: WB: fix nested redefinition of enum kbuild error

Kbuild test robot reported the following issue:

   In file included from drivers/gpu/drm/tidss/tidss_wb.c:10:0:
>> drivers/gpu/drm/tidss/tidss_wb.h:77:6: error: nested redefinition
of 'enum wb_state'
    enum wb_state {
         ^~~~~~~~
>> drivers/gpu/drm/tidss/tidss_wb.h:77:6: error: redeclaration of
'enum wb_state'
   In file included from include/linux/writeback.h:12:0,
                    from include/linux/memcontrol.h:31,
                    from include/linux/swap.h:9,
                    from include/asm-generic/tlb.h:19,
                    from arch/m68k/include/asm/tlb.h:19,
                    from arch/m68k/include/asm/motorola_pgalloc.h:5,
                    from arch/m68k/include/asm/pgalloc.h:16,
                    from include/drm/drmP.h:62,
                    from drivers/gpu/drm/tidss/tidss_wb.h:15,
                    from drivers/gpu/drm/tidss/tidss_wb.c:10:
   include/linux/backing-dev-defs.h:24:6: note: originally defined here
    enum wb_state {
         ^~~~~~~~

fixed by renaming the enum to be more specific.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Benoit Parrot <bparrot@ti.com>