ASRock E350M1: mptable.c: Include `cpu/amd/amdfam14.h` for `get_bus_conf`

When building the ASRock E350M1, the following warning is shown.

    $ make # on Jenkins (build server)
    […]
        CC         mainboard/asrock/e350m1/mptable.ramstage.o
    src/mainboard/asrock/e350m1/mptable.c: In function 'smp_write_config_table':
    src/mainboard/asrock/e350m1/mptable.c:58:3: warning: implicit declaration of function 'get_bus_conf' [-Wimplicit-function-declaration]
    […]

Including the header file `cpu/amd/amdfam14.h` declaring the
function addresses this warning.

The same change was done in the following commit for the
AMD Persimmon board.

    commit d7a696d0f2
    Author: efdesign98 <efdesign98@gmail.com>
    Date:   Thu Sep 15 15:24:26 2011 -0600

        Persimmon updates for AMD F14 rev C0

        Reviewed-on: http://review.coreboot.org/137

Change-Id: I7912571fa57f6512b10fc9b5845427fcb6eb50c0
Signed-off-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-on: http://review.coreboot.org/2966
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/mainboard/asrock/e350m1/mptable.c

@@ -24,6 +24,7 @@
 #include <arch/io.h>
 #include <string.h>
 #include <stdint.h>
+#include <cpu/amd/amdfam14.h>
 #include <SBPLATFORM.h>
 
 extern u8 bus_sb800[2];