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/arch/arm/mach-imx/imx8m/clock_imx8mq.c b/arch/arm/mach-imx/imx8m/clock_imx8mq.c
index ee18cde..52205b0 100644
--- a/arch/arm/mach-imx/imx8m/clock_imx8mq.c
+++ b/arch/arm/mach-imx/imx8m/clock_imx8mq.c
@@ -6,6 +6,7 @@
  */
 
 #include <common.h>
+#include <command.h>
 #include <asm/arch/clock.h>
 #include <asm/arch/imx-regs.h>
 #include <asm/io.h>
@@ -755,8 +756,8 @@
  * Dump some clockes.
  */
 #ifndef CONFIG_SPL_BUILD
-static int do_imx8m_showclocks(cmd_tbl_t *cmdtp, int flag, int argc,
-		       char * const argv[])
+static int do_imx8m_showclocks(struct cmd_tbl *cmdtp, int flag, int argc,
+			       char *const argv[])
 {
 	u32 freq;