staging: sm750fb: rename `hw_sm750_crtc_checkMode`

Rename `hw_sm750_crtc_checkMode` to `hw_sm750_crtc_check_mode` to
conform with kernel style guidelines as reported by checkpatch.pl

CHECK: Avoid CamelCase: <hw_sm750_crtc_checkMode>

Signed-off-by: Eric Florin <ericflorin@google.com>
Link: https://lore.kernel.org/r/546e9abb8eac1be75f47b51460ab69a5736d8a99.1747619816.git.ericflorin@google.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>