power: qpnp-bms: Remove start and end percent
power: qpnp-bms: Remove start and end percent

The BMS driver keeps track of the SoC at the start and end of
charging in order to count charge cycles. Since the functionality
was dropped, the variables are unused in QPNP-BMS.

This causes an issue in the current BMS driver as parts of the code
still rely on start_percent to be -EINVAL to signify that the battery
is not being charged.

To fix this, remove start_percent and end_percent, and use the battery
power supply's status property to determine charging status.

Change-Id: Ica4e22809fc4e0c883105233232920dd2d8b0c98
Signed-off-by: Xiaozhe Shi <4c58d9c21c42c2a4cf34b559441bd01b9c143cf4@codeaurora.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas