doc: rockchip: Fix reference the wrong defconfig name of ROC-CC-RK3308

The defconfig file for ROC-CC-RK3308 is roc-cc-rk3308_defconfig.

Fixes: 7f08bfb7 ("doc: rockchip: Add documentation for rk3308 based
boards")

Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>

doc/README.rockchip

@@ -50,7 +50,7 @@ Two RK3036 boards are supported:
 Two RK3308 boards are supported:
 
    - EVB RK3308 - use evb-rk3308 configuration
-   - ROC-CC-RK3308 - use roc-rk3308-cc configuration
+   - ROC-CC-RK3308 - use roc-cc-rk3308 configuration
 
 Two RK3328 board are supported:
 
@@ -106,7 +106,7 @@ For example:
    - Compile U-Boot
      => cd /path/to/u-boot
      => export BL31=/path/to/rkbin/bin/rk33/rk3308_bl31_v2.22.elf
-     => make roc-rk3308-cc_defconfig
+     => make roc-cc-rk3308_defconfig
      => make CROSS_COMPILE=aarch64-linux-gnu- all
      => ./tools/mkimage -n rk3308 -T rksd -d /path/to/rkbin/bin/rk33/rk3308_ddr_589MHz_uart2_m0_v1.26.bin idbloader.img
      => cat spl/u-boot-spl.bin  >> idbloader.img