ACPI: CPPC: Fix _CPC register setting issue

Since commit 60949b7 ("ACPI: CPPC: Fix MASK_VAL() usage"), _CPC
registers cannot be changed from 1 to 0.

It turns out that there is an extra OR after MASK_VAL_WRITE(), which
has already ORed prev_val with the register mask.

Remove the extra OR to fix the problem.

Fixes: 60949b7 ("ACPI: CPPC: Fix MASK_VAL() usage")
Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Link: https://patch.msgid.link/20241113103309.761031-1-zhenglifeng1@huawei.com
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: Lifeng Zheng

drivers/acpi/cppc_acpi.c

@@ -1140,7 +1140,6 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
 			return -EFAULT;
 		}
 		val = MASK_VAL_WRITE(reg, prev_val, val);
-		val |= prev_val;
 	}
 
 	switch (size) {