tpl: Kconfig: TPL_BANNER_PRINT depends on DEBUG_UART && TPL_SERIAL

As implemented in the arch/arm/mach-rockchip/tpl.c file,
the CONFIG_TPL_BANNER_PRINT option will not work
if either of these options is not enabled.

Add dependency constraints to the CONFIG_TPL_BANNER_PRINT option
definition to prevent configuration problems
where option is enabled but do not take effect.

Suggested-by: Yanjie Ren <renyanjie01@gmail.com>
Signed-off-by: Ying Sun <sunying@nj.iscas.ac.cn>
diff --git a/common/spl/Kconfig.tpl b/common/spl/Kconfig.tpl
index 1874f9d..3d6cf1e 100644
--- a/common/spl/Kconfig.tpl
+++ b/common/spl/Kconfig.tpl
@@ -43,6 +43,7 @@
 
 config TPL_BANNER_PRINT
 	bool "Enable output of the TPL banner 'U-Boot TPL ...'"
+	depends on DEBUG_UART && TPL_SERIAL
 	default y
 	help
 	  If this option is enabled, TPL will print the banner with version