ARM: add Raspberry Pi model B board, using BCM2835 SoC

The Raspberry Pi model B uses the BCM2835 SoC, has 256MB of RAM,
contains an SMSC 9512 USB LAN/Hub chip, and various IO connectors.
For more details, see http://www.raspberrypi.org/.

Various portions (cache enable, MACH_TYPE setup, RAM size limit, stack
relocation to top of RAM) extracted from work by:
Oleksandr Tymoshenko <gonzo@bluezbox.com>.

GPIO driver enablement by Vikram Narayanan <vikram186@gmail.com>.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Tom Rini <trini@ti.com>
diff --git a/boards.cfg b/boards.cfg
index a16c487..2c0c596 100644
--- a/boards.cfg
+++ b/boards.cfg
@@ -53,6 +53,7 @@
 apollon			     arm	 arm1136     apollon		 -	        omap24xx
 omap2420h4                   arm         arm1136     -                   ti             omap24xx
 tnetv107x_evm                arm         arm1176     tnetv107xevm        ti             tnetv107x
+rpi_b                        arm         arm1176     rpi_b               raspberrypi    bcm2835
 integratorap_cm720t          arm         arm720t     integrator          armltd         -           integratorap:CM720T
 integratorap_cm920t          arm         arm920t     integrator          armltd         -           integratorap:CM920T
 integratorcp_cm920t          arm         arm920t     integrator          armltd         -           integratorcp:CM920T