staging: ccree: Use platform_get_irq and devm_request_irq

staging: ccree: Use platform_get_irq and devm_request_irq

It is recommended to use managed function devm_request_irq(),
which simplifies driver cleanup paths and driver code.
This patch does the following:
(a) replace platform_get_resource(), request_irq() and corresponding
error handling with platform_get_irq() and devm_request_irq().
(b) remove struct resource pointer(res_irq) in struct ssi_drvdata as
it seems redundant.
(c) change type of member irq in struct ssi_drvdata from unsigned int
to int, as return type of platform_get_irq is int and can be used in
error handling.
(d) remove irq_registered variable from driver probe as it seems
redundant.
(e) free_irq is not required any more, devm_request_irq() free's it
on driver detach.
(f) adjust log messages accordingly and remove any blank lines.

Signed-off-by: Suniel Mahesh <sunil.m@techveda.org>
Acked-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>