twl4030 gpio cleanups

Clean up the twl4030-gpio code a bit ... mostly by shrinkage.

Remove a bunch of macros that are just obfuscating what the
TWL4030 GPIO code is doing.  Some duplicated standard macros
like BIT(); others hid trivial math (mask/shift); others were
completely unused.

Use BIT() in several places to highlight the bitmasking and
make the code more compact.

Remove pointless locking calls, sanity checks, and parenthesis.
And needless irq_chip.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>