hwmon: (occ) Fix division by zero in occ_show_power_1()

hwmon: (occ) Fix division by zero in occ_show_power_1()

In occ_show_power_1() case 1, the accumulator is divided by
update_tag without checking for zero. If no samples have been
collected yet (e.g. during early boot when the sensor block is
included but hasn't been updated), update_tag is zero, causing
a kernel divide-by-zero crash.

The 2019 fix in commit 211186cae14d ("hwmon: (occ) Fix division by
zero issue") only addressed occ_get_powr_avg() used by
occ_show_power_2() and occ_show_power_a0(). This separate code
path in occ_show_power_1() was missed.

Fix this by reusing the existing occ_get_powr_avg() helper, which
already handles the zero-sample case and uses mul_u64_u32_div()
to multiply before dividing for better precision. Move the helper
above occ_show_power_1() so it is visible at the call site.

Fixes: c10e753d43eb ("hwmon (occ): Add sensor types and versions")
Cc: stable@vger.kernel.org
Signed-off-by: Sanman Pradhan <psanman@juniper.net>
Link: https://lore.kernel.org/r/20260326224510.294619-2-sanman.pradhan@hpe.com
[groeck: Fix alignment problems reported by checkpatch]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>