efi/serial: Refactor EFI bios serial services

* Convert x86 direct port I/O to our standard gUART.
* sSerial is plainly EFI Serial or EFI Stdout
* gUART is plainly hardware serial now

Change-Id: I5730fbc0ce3427851e4e2d1d0aa8c55f7765e444
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5982
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>
Reviewed-by: Adrien Destugues <pulkomandy@pulkomandy.tk>

debug_uart fixup for arm64

Change-Id: I872e822c48d0b4675064991ba890ce6d74d15118
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5186
Reviewed-by: <oliver.ruiz.dorantes@gmail.com>
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>

system/uart: refactor debug_uart, fix arm uart

* Drop ArchUART8260 layer to reduce complexity. It's whole
existance in life was to adjust the mmio alignment.
* Fold architecture mmio alignment into DebugUart
* We could potentially pass a Init(int mmioAlignment)
arg in the future if the macros get too messy.
* Move Barrier code back a layer into DebugUART
* Fixes the arm uart and EFI build

Change-Id: I0f127d902993e9f6e6a03cac8c7c37c0363134bf
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4422
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>