serial: Use the default CONFIG_SYS_BAUDRATE_TABLE in more platforms

A number of platforms are still defining CONFIG_SYS_BAUDRATE_TABLE to
the fallback default of "{ 9600, 19200, 38400, 57600, 115200 }", but
with varying whitespace, or were introduced after the default fallback
was added.  Use the default table here.

Signed-off-by: Tom Rini <trini@konsulko.com>