riscv: Kconfig.socs: Add comments

Add trailing comments to endif and endmenu statements for better
readability.

Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Link: https://lore.kernel.org/r/20220520120232.148310-4-juergh@canonical.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Author: juergh

arch/riscv/Kconfig.socs

@@ -79,6 +79,6 @@ config SOC_CANAAN_K210_DTB_SOURCE
 	  for the DTS file that will be used to produce the DTB linked into the
 	  kernel.
 
-endif
+endif # SOC_CANAAN
 
-endmenu
+endmenu # "SoC selection"