staging: rts5208: Remove unused driver

Wei Wang from Realsil contributed this driver in 2011.

The following reasons lead to the removal:
- This driver generates maintenance workload
- Did not find minimal documentation on the web.
- No blog entries about anyone using the rts5208 and rts5288 during the
  last years.
- Did not find any device that may has it in and is still available on
  the market.

Link: https://lore.kernel.org/linux-staging/2024100943-shank-washed-a765@gregkh/T/#t
Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/20241009193250.6211-1-philipp.g.hortmann@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Philipp Hortmann

drivers/staging/Kconfig

@@ -30,8 +30,6 @@ source "drivers/staging/rtl8723bs/Kconfig"
 
 source "drivers/staging/rtl8712/Kconfig"
 
-source "drivers/staging/rts5208/Kconfig"
-
 source "drivers/staging/octeon/Kconfig"
 
 source "drivers/staging/vt6655/Kconfig"

drivers/staging/Makefile

@@ -5,7 +5,6 @@ obj-y				+= media/
 obj-$(CONFIG_FB_OLPC_DCON)	+= olpc_dcon/
 obj-$(CONFIG_RTL8723BS)		+= rtl8723bs/
 obj-$(CONFIG_R8712U)		+= rtl8712/
-obj-$(CONFIG_RTS5208)		+= rts5208/
 obj-$(CONFIG_OCTEON_ETHERNET)	+= octeon/
 obj-$(CONFIG_VT6655)		+= vt6655/
 obj-$(CONFIG_VT6656)		+= vt6656/