power: batterydata-lib: Define is_between() as a macro

Currently is_between() is defined as a function only based on
some CONFIG options whereas it can be really useful in other
places too. Remove the function definitions for is_between()
in batterydata-lib files and define it as a macro so that it
can be used just with including batterydata-lib.h.

Change-Id: Iafe8f867b97e5d6e2e8d75ad14c13bf4d4e7f7fb
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>