pc-bios: Update palcode-clipper

Update image to c87a92639b28ac42bc8f6c67443543b405dc479b,
incorporating changes for vm_time.

Signed-off-by: Richard Henderson <rth@twiddle.net>

.gitmodules

@@ -15,7 +15,7 @@
 	url = git://git.qemu.org/openbios.git
 [submodule "roms/qemu-palcode"]
 	path = roms/qemu-palcode
-	url = git://repo.or.cz/qemu-palcode.git
+	url = git://github.com/rth7680/qemu-palcode.git
 [submodule "roms/sgabios"]
 	path = roms/sgabios
 	url = git://git.qemu.org/sgabios.git

pc-bios/README

@@ -40,4 +40,4 @@
   git://repo.or.cz/s390-tools.git
 
 - The sources for the Alpha palcode image is available from:
-  git://repo.or.cz/qemu-palcode.git
+  git://github.com/rth7680/qemu-palcode.git

roms/qemu-palcode

@@ -1 +1 @@
-Subproject commit 7abb12f60eb3069019e9497e193733d77d8f0722
+Subproject commit c87a92639b28ac42bc8f6c67443543b405dc479b