arm: imx: Rework i.MX specific commands to be excluded from SPL

The "clocks" and "bootaux" commands are only usable in full U-Boot, not
SPL, so do not link them inside of SPL.  Rework a little of the bootaux
related code to make use of __weak and declare parts of it static as
it's local to the file.

Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
diff --git a/arch/arm/mach-imx/mx7ulp/clock.c b/arch/arm/mach-imx/mx7ulp/clock.c
index 77b282a..553d621 100644
--- a/arch/arm/mach-imx/mx7ulp/clock.c
+++ b/arch/arm/mach-imx/mx7ulp/clock.c
@@ -323,6 +323,7 @@
 }
 #endif
 
+#ifndef CONFIG_SPL_BUILD
 /*
  * Dump some core clockes.
  */
@@ -363,3 +364,4 @@
 	"display clocks",
 	""
 );
+#endif