Move qtlauncher applications root path and style to settings file

Moved hard-coded path and style to settings file and update
SHA of qtlauncher in boot2qt-launcher_git.bb

Task-number: QTBUG-77161
Change-Id: Ib396afe01cc24da835ab520c734ae46ea4723592
Reviewed-by: Kari Hormi <kari.hormi@qt.io>

meta-boot2qt/recipes-qt/boot2qt-addons/boot2qt-launcher/QtLauncher.conf

 [General]
 videosLocation=file:///data/videos
 defaultVideoUrl=file:///data/videos/Qt+for+Designers+and+Developers.mp4
+defaultApplicationRoot=/data/user/qt/
+style=Material

meta-boot2qt/recipes-qt/boot2qt-addons/boot2qt-launcher_git.bb

@@ -43,7 +43,7 @@ SRC_URI += " \
     file://QtLauncher.conf \
     "
 
-SRCREV = "051174fb571e889bb70056e5cab25de1d4630d76"
+SRCREV = "f89cf3ae354de42df46588d50a3ad0816cc8fc28"
 
 DEPENDS = "\
     qtbase qtdeclarative qtquickcontrols2 \