mfd: twl6030-irq: Extinguish coding style warnings

This is part of an effort to clean-up the MFD subsystem.

WARNING: please, no space before tabs
+^IRSV_INTR_OFFSET,  ^I/* Bit 12^IReserved^I^I*/$

WARNING: Missing a blank line after declarations
+       u8 unmask_value;
+       ret = twl_i2c_read_u8(TWL_MODULE_PIH, &unmask_value,

WARNING: Missing a blank line after declarations
+       u8 mask_value;
+       ret = twl_i2c_read_u8(TWL_MODULE_PIH, &mask_value,

total: 0 errors, 3 warnings, 484 lines checked

Signed-off-by: Lee Jones <lee.jones@linaro.org>