pru: Initial support for the Beaglebone PRU

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

src/pru/pru.lds

@@ -0,0 +1,9 @@
+/* Final linker script klipper.elf on the PRU */
+SECTIONS
+{
+    /* binutils on the PRU doesn't support --gc-sections so manually
+     * discard the .compile_time_request section */
+    /DISCARD/ : {
+        *( .compile_time_request )
+    }
+}