xen/arm: smccc: Add macros SMCCC_VERSION, SMCCC_VERSION_{MINOR, MAJOR}

xen/arm: smccc: Add macros SMCCC_VERSION, SMCCC_VERSION_{MINOR, MAJOR}

Add macros SMCCC_VERSION, SMCCC_VERSION_{MINOR, MAJOR} to easily convert
between a 32-bit value and a version number. The encoding is based on
2.2.2 in "Firmware interfaces for mitigation CVE-2017-5715" (ARM DEN 0070A).

Also re-use them to define ARM_SMCCC_VERSION_1_0 and ARM_SMCCC_VERSION_1_1.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>