Add alignment for the direct mode handler (#449)

It is still possible to further relax the alignment using linker script
if needed.

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
diff --git a/portable/GCC/RISC-V/portASM.S b/portable/GCC/RISC-V/portASM.S
index 56e7b88..ca50d43 100644
--- a/portable/GCC/RISC-V/portASM.S
+++ b/portable/GCC/RISC-V/portASM.S
@@ -320,6 +320,7 @@
 /*-----------------------------------------------------------*/
 
 .section .text.freertos_risc_v_trap_handler
+.align 8
 freertos_risc_v_trap_handler:
     portcontextSAVE_CONTEXT_INTERNAL