payloads/external/SeaBIOS: Bump version to 1.7.5

Change-Id: Ie4b58b739ea411035b1801348e3e73e607299846
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/6900
Tested-by: build bot (Jenkins)
Reviewed-by: Vladimir Serbinenko <phcoder@gmail.com>
diff --git a/src/Kconfig b/src/Kconfig
index 443732a..327e1bf 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -592,7 +592,7 @@
 	depends on PAYLOAD_SEABIOS
 
 config SEABIOS_STABLE
-	bool "1.7.4"
+	bool "1.7.5"
 	help
 	  Stable SeaBIOS version
 config SEABIOS_MASTER