fbdev/sbus: Build sbuslib.o if CONFIG_FB_SBUS has been selected

Avoid duplicate listings of sbuslib.o in the Makefile by building
it if CONFIG_FB_SBUS has been selected. Remove the object file from
the various drivers' build rules.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230806120926.5368-2-tzimmermann@suse.de

drivers/video/fbdev/Makefile

@@ -8,6 +8,7 @@
 obj-y				+= core/
 
 obj-$(CONFIG_FB_MACMODES)      += macmodes.o
+obj-$(CONFIG_FB_SBUS)          += sbuslib.o
 obj-$(CONFIG_FB_WMT_GE_ROPS)   += wmt_ge_rops.o
 
 # Hardware specific drivers go first
@@ -45,14 +46,14 @@ obj-$(CONFIG_FB_LE80578)          += vermilion/
 obj-$(CONFIG_FB_S3)               += s3fb.o
 obj-$(CONFIG_FB_ARK)              += arkfb.o
 obj-$(CONFIG_FB_STI)              += stifb.o
-obj-$(CONFIG_FB_FFB)              += ffb.o sbuslib.o
-obj-$(CONFIG_FB_CG6)              += cg6.o sbuslib.o
-obj-$(CONFIG_FB_CG3)              += cg3.o sbuslib.o
-obj-$(CONFIG_FB_BW2)              += bw2.o sbuslib.o
-obj-$(CONFIG_FB_CG14)             += cg14.o sbuslib.o
-obj-$(CONFIG_FB_P9100)            += p9100.o sbuslib.o
-obj-$(CONFIG_FB_TCX)              += tcx.o sbuslib.o
-obj-$(CONFIG_FB_LEO)              += leo.o sbuslib.o
+obj-$(CONFIG_FB_FFB)              += ffb.o
+obj-$(CONFIG_FB_CG6)              += cg6.o
+obj-$(CONFIG_FB_CG3)              += cg3.o
+obj-$(CONFIG_FB_BW2)              += bw2.o
+obj-$(CONFIG_FB_CG14)             += cg14.o
+obj-$(CONFIG_FB_P9100)            += p9100.o
+obj-$(CONFIG_FB_TCX)              += tcx.o
+obj-$(CONFIG_FB_LEO)              += leo.o
 obj-$(CONFIG_FB_ACORN)            += acornfb.o
 obj-$(CONFIG_FB_ATARI)            += atafb.o c2p_iplan2.o atafb_mfb.o \
                                      atafb_iplan2p2.o atafb_iplan2p4.o atafb_iplan2p8.o