LoongArch: Fix help text of CMDLINE_EXTEND in Kconfig

It is the built-in command line appended to the bootloader command line,
not the bootloader command line appended to the built-in command line.

Fixes: fa96b57 ("LoongArch: Add build infrastructure")
Signed-off-by: 谢致邦 (XIE Zhibang) <Yeking@Red54.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Author: Red54

arch/loongarch/Kconfig

@@ -386,8 +386,8 @@ config CMDLINE_BOOTLOADER
 config CMDLINE_EXTEND
 	bool "Use built-in to extend bootloader kernel arguments"
 	help
-	  The command-line arguments provided during boot will be
-	  appended to the built-in command line. This is useful in
+	  The built-in command line will be appended to the command-
+	  line arguments provided during boot. This is useful in
 	  cases where the provided arguments are insufficient and
 	  you don't want to or cannot modify them.