ARM: tegra: Remove board_init_funcs array

In a configuration that enables CONFIG_UBSAN_SANITIZE_ALL, I am getting
a section mismatch warning for tegra20:

WARNING: arch/arm/mach-tegra/built-in.o(.data+0x6e0): Section mismatch in reference from the variable board_init_funcs to the function .init.text:paz00_init()

The array is no longer useful here since there is only one entry,
so we can simply call the function directly after checking
of_machine_is_compatible(). This fixes the section mismatch
and is easier to read.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>