[media] doc-rst: add documentation for cpia2 driver

Convert the documentation to rst, merge the two files and
add to the index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/media/v4l-drivers/cpia2_overview.rst

-			Programmer's View of Cpia2
-
-Cpia2 is the second generation video coprocessor from VLSI Vision Ltd (now a
-division of ST Microelectronics).  There are two versions.  The first is the
-STV0672, which is capable of up to 30 frames per second (fps) in frame sizes
-up to CIF, and 15 fps for VGA frames.  The STV0676 is an improved version,
-which can handle up to 30 fps VGA.  Both coprocessors can be attached to two
-CMOS sensors - the vvl6410 CIF sensor and the vvl6500 VGA sensor.  These will
-be referred to as the 410 and the 500 sensors, or the CIF and VGA sensors.
-
-The two chipsets operate almost identically.  The core is an 8051 processor,
-running two different versions of firmware.  The 672 runs the VP4 video
-processor code, the 676 runs VP5.  There are a few differences in register
-mappings for the two chips.  In these cases, the symbols defined in the
-header files are marked with VP4 or VP5 as part of the symbol name.
-
-The cameras appear externally as three sets of registers. Setting register
-values is the only way to control the camera.  Some settings are
-interdependant, such as the sequence required to power up the camera. I will
-try to make note of all of these cases.
-
-The register sets are called blocks.  Block 0 is the system block.  This
-section is always powered on when the camera is plugged in.  It contains
-registers that control housekeeping functions such as powering up the video
-processor.  The video processor is the VP block.  These registers control
-how the video from the sensor is processed.  Examples are timing registers,
-user mode (vga, qvga), scaling, cropping, framerates, and so on.  The last
-block is the video compressor (VC).  The video stream sent from the camera is
-compressed as Motion JPEG (JPEGA).  The VC controls all of the compression
-parameters.  Looking at the file cpia2_registers.h, you can get a full view
-of these registers and the possible values for most of them.
-
-One or more registers can be set or read by sending a usb control message to
-the camera.  There are three modes for this.  Block mode requests a number
-of contiguous registers.  Random mode reads or writes random registers with
-a tuple structure containing address/value pairs.  The repeat mode is only
-used by VP4 to load a firmware patch.  It contains a starting address and
-a sequence of bytes to be written into a gpio port.

Documentation/media/v4l-drivers/cx18.rst

+The cx18 driver
+===============
+
+.. note::
+
+   This documentation is outdated.
+
 Some notes regarding the cx18 driver for the Conexant CX23418 MPEG
 encoder chip:
 

Documentation/media/v4l-drivers/index.rst

@@ -21,4 +21,6 @@ License".
 	fourcc
 	cardlist
 	cafe_ccic
+	cpia2
+	cx18
 	zr364xx