ACPI: RISC-V: Remove unnecessary CPPC debug message

ACPI: RISC-V: Remove unnecessary CPPC debug message

The presence or absence of the CPPC SBI extension is currently logged
on every boot. This message is not particularly useful and can clutter
the boot log. Remove this debug message to reduce noise during boot.

This change has no functional impact.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Drew Fustini <fustini@kernel.org>
Link: https://lore.kernel.org/r/20250711140013.3043463-1-sunilvl@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>