Update to EDK2 latest

* Also enable additional serial output during early init

Readme.md

@@ -50,12 +50,6 @@ to launch the UEFI Shell, or, provided you also have copied an UEFI bootloader i
 `efi/boot/bootaa64.efi`, you can let the UEFI system run that (which it should do by
 default if no action is taken).
 
-__Note:__ Provided you have relevant cooling (e.g. heatsink), it is __strongly__
-recommended that you go to setup on first boot (by pressing the <kbd>Esc</kbd> key) and
-then go through `Device Manager` &rarr; `Raspberry Pi Configuration` &rarr; 
-`CPU Configuration` to set `CPU Clock` to `<Max>`, as the default for the firmware
-is to limit the CPU clock to 600 MHz.
-
 # License
 
 The firmware (`RPI_EFI.fd`) is licensed under the current EDK2 license, which is

config.txt

@@ -1,4 +1,5 @@
 arm_64bit=1
 disable_commandline_tags=2
 enable_uart=1
+uart_2ndstage=1
 armstub=RPI_EFI.fd