qubes/ext/gui: set videoram qdb entries
qubes/ext/gui: set videoram qdb entries

This is for adjusting videoram size. See
QubesOS/qubes-gui-agent-linux@d222e16003c072bd6b420feafcbabcfa3988559a

marmarek/qubes-core-admin,QubesOS/qubes-core-admin,QubesOS/qubes-core-admin,marmarek/qubes-core-admin,marmarek/qubes-core-admin,QubesOS/qubes-core-admin