Each FFT bin value is represented as an 8 bit integer
in SAMP message. But depending on the configuration,
the FFT bin value reported by HW might exceed 8 bits.
Clamp the FFT bin value between the min and max value
which can be represented by 8 bits. For linear mode,
min and max FFT bin value which can be represented by
8 bit is 0 and U8_MAX respectively. For dBm mode, min
and max FFT bin value which can be represented by 8 bit
is S8_MIN and S8_MAX respectively.
CRs-Fixed: 3056458
Change-Id: I9ec75f781a130d3ed0d0d9393975fd5874961ce0
31da41ae4e