target/riscv/tcg: hide warn for named feats when disabling via priv_ver

target/riscv/tcg: hide warn for named feats when disabling via priv_ver

Commit 68c9e54bea handled a situation where a warning was being shown
when using the 'sifive_e' cpu when disabling the named extension zic64b.
It makes little sense to show user warnings for named extensions that
users can't control, and the solution taken was to disable zic64b
manually in riscv_cpu_update_named_features().

This solution won't scale well when adding more named features, and can
eventually end up repeating riscv_cpu_disable_priv_spec_isa_exts().

Change riscv_cpu_disable_priv_spec_isa_exts() to not show warnings when
disabling a named feature. This will accomplish the same thing we're
doing today while avoiding having two points where we're disabling
exts via priv_ver mismatch.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20241113171755.978109-2-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>