h1r9: implement additional MAX2839 functions, change some mreg definition names, fix RF gain control math

h1r9: add preliminary MAX2839 driver and accompanying header file; add some convenience macros to regs_def

h1r9: add preliminary MAX2839 register definitions

h1r9: bring-up wip

h1r9: add max2839_target.c

h1r9: add Si5351A support

h1r9: initial GPIO definitions

h1r9: use timer to detect external clock frequency

HackRF One: correct RXBB net names

HackRF One: update R83 and R84 attributes