[PATCH 1/2] Allow to override the hctosys RTC using a kernel parameter

[Roman Fietze]

Hello RTC maintainers and list members,

I would like to hear your criticism about the following two small
patches.

These patches allow to overwrite the hctosys RTC specified in the
kernel config using CONFIG_RTC_HCTOSYS_DEVICE.

The background ist, that we have two almost identical x86 boards from
MEN in Nuernberg. The first one buffers the CMOS RTC, the other one
buffers an additional Epson RX8581 I2C RTC. We would like to use the
same kernel, but the only parameter we could not overwrite when
starting the kernel or system was the RTC used to initialize the
system clock.