tools/genboardscfg.py: Do not output SPLCPU field

Prior to Kconfig, the CPU field of boards.cfg could optionally have
":SPLCPU", like "armv7:arm720t".
(Actually this syntax was only used for Tegra platform.)

Now it is not necessary at all because CPU is defined by
CONFIG_SYS_CPU in Kconfig.

For Tegra platform, the Kconfig option is described as follows:

  config SYS_CPU
          string
          default "arm720t" if SPL_BUILD
          default "armv7" if !SPL_BUILD

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/tools/genboardscfg.py b/tools/genboardscfg.py
index 99e4e87..ffef238 100755
--- a/tools/genboardscfg.py
+++ b/tools/genboardscfg.py
@@ -36,7 +36,7 @@
 # List of boards
 #   Automatically generated by %s: don't edit
 #
-# Status, Arch, CPU(:SPLCPU), SoC, Vendor, Board, Target, Options, Maintainers
+# Status, Arch, CPU, SoC, Vendor, Board, Target, Options, Maintainers
 
 ''' % __file__
 
@@ -209,12 +209,10 @@
             if not field in fields:
                 sys.exit('Error: %s is not defined in %s' % (field, defconfig))
 
-        # fix-up for aarch64 and tegra
+        # fix-up for aarch64
         if fields['arch'] == 'arm' and 'cpu' in fields:
             if fields['cpu'] == 'armv8':
                 fields['arch'] = 'aarch64'
-            if 'soc' in fields and re.match('tegra[0-9]*$', fields['soc']):
-                fields['cpu'] += ':arm720t'
 
         target, match, rear = defconfig.partition('_defconfig')
         assert match and not rear, \