config/microblaze: fix whitespace in LINK_SPEC is breaking linking

whitespace is causing the intended output of `-dT xilinx.ld%s` to be split
and takeninto if-exists-then-else as 2nd and 3rd arguments so LINK_SPEC
emits `-dT` when xilinx.ld is found, and emits xilinx.ld when not found.

Signed-off-by: Alp Sayin <alpsayin@gmail.com>

Author: alpsayin

gcc/config/microblaze/microblaze.h

@@ -115,7 +115,7 @@ extern enum pipeline_type microblaze_pipe;
   %{Zxl-mode-xmdstub:-defsym _TEXT_START_ADDR=0x800} \
   %{mxl-mode-xmdstub:-defsym _TEXT_START_ADDR=0x800} \
   %{mxl-gp-opt:%{G*}} %{!mxl-gp-opt: -G 0} \
-  %{!r:%{!T*: %:if-exists-then-else(%:find-file(xilinx.ld) -dT xilinx.ld%s)}}"
+  %{!r:%{!T*: %:if-exists-then-else(%:find-file(xilinx.ld) -dTxilinx.ld%s)}}"
 
 /* Specs for the compiler proper  */