um: Fix Kconfig indentation

Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
	$ sed -e 's/^        /\t/' -i */Kconfig

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.co.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index fec6b4c..2a6d04fc 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -153,7 +153,7 @@
 	  It is possible to reduce the stack to 1 for 64BIT and 0 for 32BIT on
 	  older (pre-2017) CPUs. It is not recommended on newer CPUs due to the
 	  increase in the size of the state which needs to be saved when handling
-          signals.
+	  signals.
 
 config MMAPPER
 	tristate "iomem emulation driver"