tree: Drop repeated words

Found-by: linter
Change-Id: I7c6d0887a45fdb4b6de294770a7fdd5545a9479b
Signed-off-by: Alexander Goncharov <chat@joursoir.net>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/72795
Reviewed-by: Nicholas Chin <nic.c3.14@gmail.com>
Reviewed-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Reviewed-by: Erik van den Bogaert <ebogaert@eltan.com>
Reviewed-by: Frans Hendriks <fhendriks@eltan.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/Kconfig b/src/Kconfig
index 8246a17..16f7881 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -562,7 +562,7 @@
 	# Default value set at the end of the file
 	help
 	  This is the part of the ROM actually managed by CBFS, located at the
-	  end of the ROM (passed through cbfstool -o) on x86 and at at the start
+	  end of the ROM (passed through cbfstool -o) on x86 and at the start
 	  of the ROM (passed through cbfstool -s) everywhere else. It defaults
 	  to span the whole ROM on all but Intel systems that use an Intel Firmware
 	  Descriptor.  It can be overridden to make coreboot live alongside other