meta-ked: sparkle: Set PV and use commit hash in SRCREV instead of tag

This solves the following error message with Kirkstone:

Bitbake Fetcher Error: FetchError("Recipe uses a floating tag/branch 'rel_1.9.0' for repo 'git.kontron-electronics.de/sw/misc/apps/sparkle.git' without a fixed SRCREV yet doesn't call bb.fetch2.get_srcrev() (use SRCPV in PV for OE).", None)

layers/meta-ked/recipes-ked/sparkle/sparkle.bb → layers/meta-ked/recipes-ked/sparkle/sparkle_1.9.0.bb

@@ -18,8 +18,7 @@ SRC_URI = " \
      file://sparkle-dut-mx6ul-combox.cfg \
 "
 
-#SRCREV = "0b2fc0466aa05626e6721d8942b5e0b35cb1b062"
-SRCREV = "rel_1.9.0"
+SRCREV = "0b2fc0466aa05626e6721d8942b5e0b35cb1b062"
 SRCBRANCH = "master"
 
 SRC_URI[md5sum] = "8d340c2a203dc3a2a3e912a9d681b311"