dev/psci: Fix a function name

dd a missing underscore to arm_smccc_1_2_* to fix the GCC build.

Sponsored by: Arm Ltd

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

arm_smcc_1_2_*: Don't trash SP and X19 if no return value structure.

Jumping direct to ret was not restoring the saved value of x19 and was
also not adjusting sp to discard the two saved registers.

Reviewed by: andrew
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D37922

arm64: Enabling new hypercalls using HvCallSetVpRegisters and HvCallGetVpRegisters

Enabling HvCallSetVpRegisters and HvCallGetVpRegisters for hypercalls to
read and write to specific MSRs. This is required for implementing wrmsr
and rdmsr, which is required for Hyper-V vmbus driver for ARM64.

Also we need to use arm smccc hvc 1.2 version as we need to access
registers beyond X0-X3 for HvCallGetVpRegisters. Currently scoping
it only for Hyper-V.

Reviewed by: lwhsu, andrew, whu
Tested by: Souradeep Chakrabarti <schakrabarti@microsoft.com>
Signed-off-by: Souradeep Chakrabarti <schakrabarti@microsoft.com>
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D36256

Merge the common parts of the SMCCC handlers

To simplify adding new handlers merge the common parts of the functions
used to call into the arm SMCCC firmware.

Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D36297

Add generic arm/arm64 secure-monitor SMCCC interface and switch
PSCI code to use it.

This interface will also be used by Intel Stratix 10 platform.

This was not tested on arm due to lack of PSCI-enabled arm hardware
lying around.

Reviewed by: andrew
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D21439