upgrade to linux 2.6.21.4

SVN-Revision: 7563

include/kernel-version.mk

@@ -6,9 +6,9 @@ ifeq ($(LINUX_VERSION),)
     LINUX_RELEASE:=1
     LINUX_KERNEL_MD5SUM:=f59665540a7f3351ea416a0dad104b55
   else
-    LINUX_VERSION:=2.6.21.1
+    LINUX_VERSION:=2.6.21.4
     LINUX_RELEASE:=1
-    LINUX_KERNEL_MD5SUM:=a28b78793cd368592f7873bf36cb38b0
+    LINUX_KERNEL_MD5SUM:=c50995d713ba2d73f148e10073342568
   endif
 endif
 KERNEL:=2.$(word 2,$(subst ., ,$(strip $(LINUX_VERSION))))