soc: riscv: telink_b91: fix required headers

The linker script is using the DT API, which was previously included via
<soc.h>.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>

soc/riscv/riscv-privilege/telink_b91/linker.ld

@@ -8,8 +8,8 @@
  * @brief Linker script for the Telink B91 SoC
  */
 
-#include <soc.h>
 #include <autoconf.h>
+#include <devicetree.h>
 #include <linker/linker-tool.h>
 
 MEMORY