tools/bison: update to 3.7.6

Signed-off-by: Rosen Penev <rosenp@gmail.com>

tools/bison/Makefile

@@ -7,11 +7,11 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=bison
-PKG_VERSION:=3.7.4
+PKG_VERSION:=3.7.6
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=@GNU/$(PKG_NAME)
-PKG_HASH:=a3b5813f48a11e540ef26f46e4d288c0c25c7907d9879ae50e430ec49f63c010
+PKG_HASH:=67d68ce1e22192050525643fc0a7a22297576682bef6a5c51446903f5aeef3cf
 
 HOST_BUILD_PARALLEL:=1