am335x: Fix the address of the pinmux registers.

The pinmux register data structure describes a subset of the control module
registers, but the address which pointed to the base of the pinmux registers
was actually being set to the beginning of all the control module registers,
not just those having to do with the pinmux. With this address fixed, the UART
now works on the beaglebone black.

Change-Id: I7c99b6f37d7da359af074127cd0c1a86fda2d9a0
Signed-off-by: Gabe Black <gabeblack@chromium.org>
Reviewed-on: http://review.coreboot.org/3574
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/cpu/ti/am335x/pinmux.h

@@ -54,7 +54,7 @@ void am335x_pinmux_mii1(void);
 
 void am335x_pinmux_nand(void);
 
-#define AM335X_PINMUX_REG_ADDR 0x44e10000
+#define AM335X_PINMUX_REG_ADDR 0x44e10800
 
 struct am335x_pinmux_regs {
 	uint32_t gpmc_ad0;