arm64: dts: meson: fix spi-max-frequency on Khadas VIM2

The max frequency for the w25q32 (VIM v1.2) and w25q128 (VIM v1.4) spifc
chip should be 104Mhz not 30MHz.

Fixes: b8b74dda ("ARM64: dts: meson-gxm: Add support for Khadas VIM2")
Signed-off-by: Artem Lapkin <art@khadas.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Link: https://lore.kernel.org/r/20201125024001.19036-1-christianshewitt@gmail.com