configs: Escape hash characters

Change-Id: I5b21d7a5310767ea2fd3aebd81b83044e8eec7f2
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/18785
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Philippe Mathieu-Daudé <philippe.mathieu.daude@gmail.com>
Reviewed-by: Martin Roth <martinroth@google.com>
diff --git a/configs/broadwell b/configs/broadwell
index 9921ff8..a8aa58a 100644
--- a/configs/broadwell
+++ b/configs/broadwell
@@ -2,4 +2,4 @@
 CONFIG_GFX_GMA_CPU_VARIANT	= Normal
 CONFIG_GFX_GMA_INTERNAL_PORT	= DP
 CONFIG_GFX_GMA_ANALOG_I2C_PORT	= PCH_DAC
-CONFIG_GFX_GMA_DEFAULT_MMIO	= 16#e000_0000#
+CONFIG_GFX_GMA_DEFAULT_MMIO	= 16\#e000_0000\#