skiboot: Bump to 6.0.13

Bump skiboot to 6.0.13 which contains the commit that adds the
--skip flag to pflash[0] plus the release notes[1]:

[0] 977aa1e pflash: Add --skip option for reading
[1] e550528 skiboot v6.0.13 release notes

Tested: Copied the built pflash binary to romulus and
verified it had the new flag.

(From meta-openpower rev: 13f6cad2d40fd06340500348e06097cdfb39eca1)

Change-Id: I04d960471e0dfb728774b3eb6b5953c1b5eabcc2
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-openpower/recipes-bsp/skiboot/skiboot.inc b/meta-openpower/recipes-bsp/skiboot/skiboot.inc
index 2fdbba1..7ac1c08 100644
--- a/meta-openpower/recipes-bsp/skiboot/skiboot.inc
+++ b/meta-openpower/recipes-bsp/skiboot/skiboot.inc
@@ -1,14 +1,14 @@
 HOMEPAGE = "https://github.com/open-power"
 LICENSE = "Apache-2.0"
 
-SRC_URI += "git://github.com/open-power/skiboot.git;nobranch=1"
+SRC_URI += "git://github.com/open-power/skiboot.git"
 
 FILESEXTRAPATHS_append := "${THISDIR}/skiboot:"
 
 LIC_FILES_CHKSUM = "file://${S}/LICENCE;md5=3b83ef96387f14655fc854ddc3c6bd57"
 
-SRCREV = "452998f4be5973d8884e3db5aa362bf40e11467a"
-PV = "6.1+git${SRCPV}"
+SRCREV = "30f8a6006de45fadedd80c98059b63d3874a5269"
+PV = "6.0.13+git${SRCPV}"
 
 S = "${WORKDIR}/git"