docs-rst: core_api: move driver-specific stuff to drivers_api

There are several stuff there that are actually driver-specific.

Move those to the driver_api book.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/driver-api/index.rst

@@ -27,6 +27,7 @@ available subsections can be seen below.
    iio/index
    input
    usb
+   pci
    spi
    i2c
    hsi
@@ -36,6 +37,7 @@ available subsections can be seen below.
    80211/index
    uio-howto
    firmware/index
+   misc_devices
 
 .. only::  subproject and html