Kconfig: Remove trailing whitespaces in prompt

Remove additional trailing whitespaces in prompt reported by kconfiglib:

warning: DM_PMIC_SANDBOX (defined at drivers/power/pmic/Kconfig:133) has
leading or trailing whitespace in its prompt
warning: <choice> (defined at dts/Kconfig:204) has leading or trailing
whitespace in its prompt

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Felix Brack <fb@ltec.ch>
diff --git a/drivers/power/pmic/Kconfig b/drivers/power/pmic/Kconfig
index d504c28..cba48e1 100644
--- a/drivers/power/pmic/Kconfig
+++ b/drivers/power/pmic/Kconfig
@@ -131,7 +131,7 @@
 	Binding info: doc/device-tree-bindings/pmic/s2mps11.txt
 
 config DM_PMIC_SANDBOX
-	bool "Enable Driver Model for emulated Sandbox PMIC "
+	bool "Enable Driver Model for emulated Sandbox PMIC"
 	depends on DM_PMIC
 	---help---
 	Enable the driver for Sandbox PMIC emulation. The emulated PMIC device