[OE_BP] Revert "[pvr] empty string as default value for pvrpowermanagement.setwakeupcmd"

This reverts commit 799d6ff03b32ca7a6f4a398fa064f412e8cc8144.
[OE_BP] disable ALT+TAB globally
[OE_BP XB-AML-dfa17e4] feature, add as.xml control over the delay until busy dialog is shown when starting video playback
[OE_BP PR2791] SoftAE: make sure we hold sink lock when we consume and write to sink

This make sure that sink delay and buffers are kept in line.
[OE_BP PR2791] SoftAE: let SoftAEStream share SoftAE stream lock

This avoids holding an internal stream lock, while soft ae
is trying to read out new frames and allow us to properly
hold lock while requesting delays.
[OE_BP PR2791] softae: use correct number of bytes when consuming from src buffer
[OE_BP PR2791] softae: add fail safe to WriteSink to avoid deadlocking on broken output
[OE_BP PR2791] softae: verify we have enough samples in WriteSink

Some other thread may have killed the buffer behind our backs
[OE_BP PR2791] softae: make sure we hold sink lock when we kill of sinks
[OE_BP XB-546fccd] dvdplayer: clock was starting before expected
[OE_BP PR2969] AESinkAlsa: Make sure to reinit but return false if format might be changing