Revert "target: Support whitespaces in target attr/pragma."

This reverts commit 6b34f5c5ec75823d656b6882f12d46248402a2aa.

gcc/config/aarch64/aarch64.c

@@ -17634,7 +17634,6 @@ aarch64_process_one_target_attr (char *arg_str)
 
   char *str_to_check = (char *) alloca (len + 1);
   strcpy (str_to_check, arg_str);
-  str_to_check = strip_whitespaces (str_to_check, &len);
 
   /* We have something like __attribute__ ((target ("+fp+nosimd"))).
      It is easier to detect and handle it explicitly here rather than going

gcc/testsuite/gcc.target/aarch64/pr102375.c

@@ -1,4 +0,0 @@
-/* PR target/102375 */
-/* { dg-do compile } */
-
-void calculate(void) __attribute__ ((target ("+sve, +sve2")));