librem5-evk: Drop the panel power on delay

This saves 0.5s on boot and we have the timing in the panel driver
correct now so it's not needed.

Signed-off-by: Guido Günther <guido.gunther@puri.sm>
1 job for <span class="ref-name">panel-delay</span> in 32 minutes and 14 seconds
Status Job ID Name Coverage
  Build
passed #7833
librem5
build:aarch64

00:32:14