mt6765-common: rootdir: Elevate read permissions for mtk_cmdq and mdp_sync

Apparently on AOSP builds, these nodes when read by the hals
with O_RDONLY attribute, need an elevated read permission, which
is apparently unneeded on mtk builds/stock rom.

This fixes video playback/OMX

Signed-off-by: Vaisakh Murali <mvaisakh@statixos.com>
Change-Id: I7f358d0037de569a4eb038e5ac2a17b7651d307d