radio: RTC6226: Add support for RTC6226 FM chip

Add support for Richwave's RTC6226 FM chip based
on I2C. Add enable, disable, tune, seek and scan
functionality.

Signed-off-by: tiantsai chang <changtt@richwave.com.tw>
Git-commit: 7066fd96dfa476c7131cfb791f59a09397017f40
Git-repo:  https://gitlab.com/richwavegit/rtc6226/


CRs-Fixed: 2513338
Change-Id: Ib91e5612c6cdbae2200b16dedd048b953b6dce64
Signed-off-by: himta ram <hram@codeaurora.org>