rtc: ds1307: Add support for Epson RX8130CE

Add support for yet another RTC chip, Epson RX8130CE. This time around,
the chip has slightly permutated registers and also the register starts
at 0x10 instead of 0x0 .

So far, we only support the RTC and NVRAM parts of the chip, Alarm and
Timer is not supported.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>