command: Remove the cmd_tbl_t typedef

We should not use typedefs in U-Boot. They cannot be used as forward
declarations which means that header files must include the full header to
access them.

Drop the typedef and rename the struct to remove the _s suffix which is
now not useful.

This requires quite a few header-file additions.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/cmd/riscv/exception.c b/cmd/riscv/exception.c
index 547fb7d..3c8dbbe 100644
--- a/cmd/riscv/exception.c
+++ b/cmd/riscv/exception.c
@@ -8,14 +8,14 @@
 #include <common.h>
 #include <command.h>
 
-static int do_undefined(cmd_tbl_t *cmdtp, int flag, int argc,
-			char * const argv[])
+static int do_undefined(struct cmd_tbl *cmdtp, int flag, int argc,
+			char *const argv[])
 {
 	asm volatile (".word 0xffffffff\n");
 	return CMD_RET_FAILURE;
 }
 
-static cmd_tbl_t cmd_sub[] = {
+static struct cmd_tbl cmd_sub[] = {
 	U_BOOT_CMD_MKENT(undefined, CONFIG_SYS_MAXARGS, 1, do_undefined,
 			 "", ""),
 };