media: dvb-frontends: add LNBH29 LNB supply driver

Add support for STMicroelectronics LNBH29 LNB supply driver.

Signed-off-by: Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>