arm64: dts: msm8994-angler: fix the memory map

Add reserved regions for memory hole and tz app mem to prevent
rebooting. Also enable cont_splash_mem, it is the same as the
generic 8994 one.

Reported-by: Petr Vorel <petr.vorel@gmail.com>
Signed-off-by: Dominik Kobinski <dominikkobinski314@gmail.com>
Reviewed-by: Petr Vorel <petr.vorel@gmail.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221230194845.57780-1-dominikkobinski314@gmail.com