ANDROID: arm64: Disallow use of backported SYS_FIELD_*() access macros

These are dangerous because they assume mask macros are pre-shifted,
GENMASK style. Most of the masks in this kernel tree are not shifted.
Avoid accidental buggy backports in future by turning the SYS_FIELD
accessors into BUILD_BUG().

Signed-off-by: Keir Fraser <keirf@google.com>
Bug: 233588291
Fixes: 1bf4f91a ("UPSTREAM: arm64/sysreg: Introduce helpers for access to sysreg fields")
Change-Id: I647a66d59279e69c916f66b42705fc20cd256fa8