staging: sm750fb: rename getChipType to sm750_get_chip_type

Rename CamelCased function getChipType to sm750_get_chip_type
(prefex with sm750 in order to make the context of
the function clear).

This issue was found by checkpatch.pl

Signed-off-by: Moshe Green <mgmoshes@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>