MIPS: remove CONFIG_MIPS_LD_CAN_LINK_VDSO

Given commit e4412739472b ("Documentation: raise minimum supported
version of binutils to 2.25"), CONFIG_MIPS_LD_CAN_LINK_VDSO is always
'y'.

Signed-off-by: Masahiro Yamada <[e-mail]>
Reviewed-by: Nathan Chancellor <[e-mail]>
Reviewed-by: Philippe Mathieu-Daudé <[e-mail]>
Signed-off-by: Thomas Bogendoerfer <[e-mail]>

arch/mips/vdso/Kconfig

···
-# For the pre-R6 code in arch/mips/vdso/vdso.h for locating
-# the base address of VDSO, the linker will emit a R_MIPS_PC32
-# relocation in binutils > 2.25 but it will fail with older versions
-# because that relocation is not supported for that symbol. As a result
-# of which we are forced to disable the VDSO symbols when building
-# with < 2.25 binutils on pre-R6 kernels. For more references on why we
-# can't use other methods to get the base address of VDSO please refer to
-# the comments on that file.
-#
 # GCC (at least up to version 9.2) appears to emit function calls that make use
 # of the GOT when targeting microMIPS, which we can't use in the VDSO due to
 # the lack of relocations. As such, we disable the VDSO for microMIPS builds.
 
-config MIPS_LD_CAN_LINK_VDSO
-	def_bool LD_VERSION >= 22500 || LD_IS_LLD
-
 config MIPS_DISABLE_VDSO
-	def_bool CPU_MICROMIPS || (!CPU_MIPSR6 && !MIPS_LD_CAN_LINK_VDSO)
+	def_bool CPU_MICROMIPS

arch/mips/vdso/Makefile

···
 CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE)
 
 ifdef CONFIG_MIPS_DISABLE_VDSO
-  ifndef CONFIG_MIPS_LD_CAN_LINK_VDSO
-    $(warning MIPS VDSO requires binutils >= 2.25)
-  endif
   obj-vdso-y := $(filter-out vgettimeofday.o, $(obj-vdso-y))
 endif