misc: spica-dpram: Remove private header file

All the definitions from the header have been used only by driver code,
so they could be moved there.

This patch removes the unnecessary private header file.

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
ARM: s3c64xx: gt_i5700: Update comment about WLAN and OneDRAM irq trigger

After last changes WLAN and OneDRAM interrupts use falling edge
triggering.

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
misc: spica-dpram: Clean up SIM card detection code

This patch reworks handling of SIM card detection to use a much cleaner
approach and be more reliable.

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>