x11-libs/gtk+: Move adwaita-icon-theme to PDEPEND to fix circular dep

adwaita-icon-theme requires gtk+:3 at build time to properly generate the
symbolic PNG icons from SVG files with the gtk-encode-symbolic-svg tool,
which is shipped by gtk+:3. Thus adwaita-icon-theme depend in gtk+:3 can
not be a runtime only RDEPEND, but has to be PDEPEND due to PMS rule:
"Runtime dependencies (RDEPEND). These must be installed and usable before
the results of an ebuild merging are treated as usable."
Should be fine to install adwaita-icon-theme afterwards in the order, to
satisfy default theme icons.

Gentoo-bug: 628076
Package-Manager: Portage-2.3.6, Repoman-2.3.2

x11-libs/gtk+/gtk+-3.22.17.ebuild

@@ -86,10 +86,10 @@ RDEPEND="${COMMON_DEPEND}
  >=dev-util/gtk-update-icon-cache-3
  !<gnome-base/gail-1000
  !<x11-libs/vte-0.31.0:2.90
- >=x11-themes/adwaita-icon-theme-3.14
 "
 # librsvg for svg icons (PDEPEND to avoid circular dep), bug #547710
 PDEPEND="
+ >=x11-themes/adwaita-icon-theme-3.14
  gnome-base/librsvg[${MULTILIB_USEDEP}]
  vim-syntax? ( app-vim/gtk-syntax )
 "

x11-libs/gtk+/gtk+-3.22.19.ebuild

@@ -86,11 +86,11 @@ RDEPEND="${COMMON_DEPEND}
  >=dev-util/gtk-update-icon-cache-3
  !<gnome-base/gail-1000
  !<x11-libs/vte-0.31.0:2.90
- >=x11-themes/adwaita-icon-theme-3.14
 "
 # librsvg for svg icons (PDEPEND to avoid circular dep), bug #547710
 PDEPEND="
  gnome-base/librsvg[${MULTILIB_USEDEP}]
+ >=x11-themes/adwaita-icon-theme-3.14
  vim-syntax? ( app-vim/gtk-syntax )
 "